From 51581681c27e7bfc2c0e21de256cba96f0878c37 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 18 Jul 2026 16:34:02 +0000
Subject: [PATCH 1/7] SOLR-18310: Switch opentelemetry module from OkHttp
 sender to JDK HTTP sender

---
 .../update-opentelemetry-exporter.yml         | 33 +++++++++++++++++++
 gradle/libs.versions.toml                     |  1 +
 .../metrics/otel/MetricExporterFactory.java   |  2 +-
 solr/cross-dc-manager/gradle.lockfile         | 25 +-------------
 solr/licenses/grpc-netty-1.82.0.jar.sha1      |  1 -
 .../netty-codec-http2-4.2.15.Final.jar.sha1   |  1 -
 .../netty-codec-socks-4.2.15.Final.jar.sha1   |  1 -
 .../netty-handler-proxy-4.2.15.Final.jar.sha1 |  1 -
 ...emetry-exporter-sender-jdk-1.56.0.jar.sha1 |  1 +
 ...try-exporter-sender-okhttp-1.56.0.jar.sha1 |  1 -
 ...proto-google-common-protos-2.64.1.jar.sha1 |  1 -
 solr/modules/opentelemetry/build.gradle       | 15 +++++----
 solr/modules/opentelemetry/gradle.lockfile    | 28 ++--------------
 .../opentelemetry/OtelTracerConfigurator.java |  2 +-
 .../pages/distributed-tracing.adoc            | 17 ++++++----
 .../pages/major-changes-in-solr-10.adoc       |  7 ++++
 16 files changed, 65 insertions(+), 72 deletions(-)
 create mode 100644 changelog/unreleased/update-opentelemetry-exporter.yml
 delete mode 100644 solr/licenses/grpc-netty-1.82.0.jar.sha1
 delete mode 100644 solr/licenses/netty-codec-http2-4.2.15.Final.jar.sha1
 delete mode 100644 solr/licenses/netty-codec-socks-4.2.15.Final.jar.sha1
 delete mode 100644 solr/licenses/netty-handler-proxy-4.2.15.Final.jar.sha1
 create mode 100644 solr/licenses/opentelemetry-exporter-sender-jdk-1.56.0.jar.sha1
 delete mode 100644 solr/licenses/opentelemetry-exporter-sender-okhttp-1.56.0.jar.sha1
 delete mode 100644 solr/licenses/proto-google-common-protos-2.64.1.jar.sha1

diff --git a/changelog/unreleased/update-opentelemetry-exporter.yml b/changelog/unreleased/update-opentelemetry-exporter.yml
new file mode 100644
index 000000000000..c459197a9e44
--- /dev/null
+++ b/changelog/unreleased/update-opentelemetry-exporter.yml
@@ -0,0 +1,33 @@
+# (DELETE ALL COMMENTS UP HERE AFTER FILLING THIS IN
+
+# See https://github.com/apache/solr/blob/main/dev-docs/changelog.adoc
+
+# If the change is minor, don't bother adding a changelog entry.
+# For `other` type entries, the threshold to bother with a changelog entry should be even higher.
+
+# title:
+#  * The audience is end-users and administrators, not committers.
+#  * Be short and focused on the user impact.  Multiple sentences is fine!
+#  * For technical/geeky details, prefer the commit message instead of changelog.
+#  * Reference JIRA issues like `SOLR-12345`, or if no JIRA but have a GitHub PR then `PR#12345`.
+
+# type:
+#  `added` for new features/improvements, opt-in by the user typically documented in the ref guide
+#  `changed` for improvements; not opt-in
+#  `fixed` for improvements that are deemed to have fixed buggy behavior
+#  `deprecated` for marking things deprecated
+#  `removed` for code removed
+#  `dependency_update` for updates to dependencies
+#  `other` for anything else, like large/significant refactorings, build changes,
+#    test infrastructure, or documentation.
+#    Most such changes are too small/minor to bother with a changelog entry.
+
+title: >
+  SOLR-18310: The opentelemetry module now uses the JDK HTTP sender instead of OkHttp, reducing
+  transitive dependencies. The default OTLP export protocol has changed from gRPC (port 4317) to
+  HTTP/Protobuf (port 4318). gRPC transport is no longer supported out of the box; users who need
+  it can add the required gRPC, OkHttp, and Protobuf jars to the opentelemetry module's lib directory.
+type: dependency_update
+authors:
+  - name: copilot-swe-agent[bot]
+
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index ad0aa4db6103..195905469d91 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -486,6 +486,7 @@ opentelemetry-api = { module = "io.opentelemetry:opentelemetry-api", version.ref
 opentelemetry-bom = { module = "io.opentelemetry:opentelemetry-bom", version.ref = "opentelemetry" }
 opentelemetry-context = { module = "io.opentelemetry:opentelemetry-context", version.ref = "opentelemetry" }
 opentelemetry-exporter-otlp = { module = "io.opentelemetry:opentelemetry-exporter-otlp", version.ref = "opentelemetry" }
+opentelemetry-exporter-sender-jdk = { module = "io.opentelemetry:opentelemetry-exporter-sender-jdk", version.ref = "opentelemetry" }
 opentelemetry-exporter-prometheus = { module = "io.opentelemetry:opentelemetry-exporter-prometheus", version.ref = "opentelemetry-prometheus" }
 opentelemetry-runtime-telemetry = { module = "io.opentelemetry.instrumentation:opentelemetry-runtime-telemetry-java17", version.ref = "opentelemetry-runtime-telemetry" }
 opentelemetry-sdk = { module = "io.opentelemetry:opentelemetry-sdk", version.ref = "opentelemetry" }
diff --git a/solr/core/src/java/org/apache/solr/metrics/otel/MetricExporterFactory.java b/solr/core/src/java/org/apache/solr/metrics/otel/MetricExporterFactory.java
index d0ac8219aa33..e6f1f24e85c2 100644
--- a/solr/core/src/java/org/apache/solr/metrics/otel/MetricExporterFactory.java
+++ b/solr/core/src/java/org/apache/solr/metrics/otel/MetricExporterFactory.java
@@ -25,7 +25,7 @@ public interface MetricExporterFactory {
       Boolean.parseBoolean(EnvUtils.getProperty("solr.metrics.otlpExporterEnabled", "false"));
 
   public static final String OTLP_EXPORTER_PROTOCOL =
-      EnvUtils.getProperty("solr.metrics.otlpExporterProtocol", "grpc");
+      EnvUtils.getProperty("solr.metrics.otlpExporterProtocol", "http");
 
   public static final int OTLP_EXPORTER_INTERVAL =
       Integer.parseInt(EnvUtils.getProperty("solr.metrics.otlpExporterInterval", "60000"));
diff --git a/solr/cross-dc-manager/gradle.lockfile b/solr/cross-dc-manager/gradle.lockfile
index 829aa69a750e..80f332fc2bd4 100644
--- a/solr/cross-dc-manager/gradle.lockfile
+++ b/solr/cross-dc-manager/gradle.lockfile
@@ -19,8 +19,6 @@ com.fasterxml.woodstox:woodstox-core:7.2.1=jarValidation,runtimeClasspath,runtim
 com.github.ben-manes.caffeine:caffeine:3.2.4=annotationProcessor,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testRuntimeClasspath
 com.github.kevinstern:software-and-algorithms:1.0=annotationProcessor,errorprone,testAnnotationProcessor
 com.github.luben:zstd-jni:1.5.6-4=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-com.google.android:annotations:4.1.1.4=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.google.api.grpc:proto-google-common-protos:2.64.1=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 com.google.auto.service:auto-service-annotations:1.0.1=annotationProcessor,errorprone,testAnnotationProcessor
 com.google.auto.value:auto-value-annotations:1.11.1=annotationProcessor,errorprone,testAnnotationProcessor
 com.google.auto:auto-common:1.2.2=annotationProcessor,errorprone,testAnnotationProcessor
@@ -40,10 +38,6 @@ com.google.protobuf:protobuf-java:4.35.1=annotationProcessor,errorprone,jarValid
 com.j256.simplemagic:simplemagic:1.17=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 com.jayway.jsonpath:json-path:3.0.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 com.lmax:disruptor:4.0.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-com.squareup.okhttp3:okhttp-jvm:5.4.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.squareup.okhttp3:okhttp:5.4.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.squareup.okio:okio-jvm:3.17.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.squareup.okio:okio:3.17.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 com.tdunning:t-digest:3.3=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 com.thoughtworks.paranamer:paranamer:2.8.3=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 com.typesafe.scala-logging:scala-logging_2.13:3.9.5=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
@@ -58,23 +52,9 @@ commons-validator:commons-validator:1.10.1=jarValidation,runtimeClasspath,runtim
 io.dropwizard.metrics:metrics-core:4.2.39=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.github.eisop:dataflow-errorprone:3.41.0-eisop1=annotationProcessor,errorprone,testAnnotationProcessor
 io.github.java-diff-utils:java-diff-utils:4.12=annotationProcessor,errorprone,testAnnotationProcessor
-io.grpc:grpc-api:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-context:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-core:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-netty:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-protobuf-lite:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-protobuf:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-stub:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-util:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-bom:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.netty:netty-buffer:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-codec-base:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
-io.netty:netty-codec-compression:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-codec-http2:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-codec-http:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-codec-socks:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.netty:netty-common:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
-io.netty:netty-handler-proxy:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.netty:netty-handler:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-resolver:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-tcnative-boringssl-static:2.0.79.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
@@ -97,7 +77,7 @@ io.opentelemetry:opentelemetry-exporter-common:1.56.0=jarValidation,runtimeClass
 io.opentelemetry:opentelemetry-exporter-otlp-common:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-exporter-otlp:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-exporter-prometheus:1.56.0-alpha=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-io.opentelemetry:opentelemetry-exporter-sender-okhttp:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
+io.opentelemetry:opentelemetry-exporter-sender-jdk:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-common:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-extension-autoconfigure:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
@@ -105,7 +85,6 @@ io.opentelemetry:opentelemetry-sdk-logs:1.56.0=jarValidation,runtimeClasspath,ru
 io.opentelemetry:opentelemetry-sdk-metrics:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-trace:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-io.perfmark:perfmark-api:0.27.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.prometheus:prometheus-metrics-exposition-formats:1.1.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.prometheus:prometheus-metrics-model:1.1.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.sgr:s2-geometry-library-java:1.0.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
@@ -217,8 +196,6 @@ org.glassfish.jersey.media:jersey-media-json-jackson:4.0.2=jarValidation,runtime
 org.glassfish.jersey:jersey-bom:4.0.2=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 org.hamcrest:hamcrest:3.0=jarValidation,testCompileClasspath,testRuntimeClasspath
 org.javassist:javassist:3.30.2-GA=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-org.jetbrains.kotlin:kotlin-stdlib:2.2.21=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-org.jetbrains:annotations:26.1.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 org.jspecify:jspecify:1.0.0=annotationProcessor,compileClasspath,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testCompileClasspath,testRuntimeClasspath
 org.junit.jupiter:junit-jupiter-api:5.6.2=jarValidation,testRuntimeClasspath
 org.junit.platform:junit-platform-commons:1.6.2=jarValidation,testRuntimeClasspath
diff --git a/solr/licenses/grpc-netty-1.82.0.jar.sha1 b/solr/licenses/grpc-netty-1.82.0.jar.sha1
deleted file mode 100644
index ad9bc971adda..000000000000
--- a/solr/licenses/grpc-netty-1.82.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-bb2e92c518f044a194fbc06a769a1ec89efa3544
diff --git a/solr/licenses/netty-codec-http2-4.2.15.Final.jar.sha1 b/solr/licenses/netty-codec-http2-4.2.15.Final.jar.sha1
deleted file mode 100644
index 68fe44b7d9b2..000000000000
--- a/solr/licenses/netty-codec-http2-4.2.15.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-c70540243427c8c952473f55813c6d459817de42
diff --git a/solr/licenses/netty-codec-socks-4.2.15.Final.jar.sha1 b/solr/licenses/netty-codec-socks-4.2.15.Final.jar.sha1
deleted file mode 100644
index 6adae6986809..000000000000
--- a/solr/licenses/netty-codec-socks-4.2.15.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-5d6dc38231104f28b6ba48b77d2f90b93cdb6fe7
diff --git a/solr/licenses/netty-handler-proxy-4.2.15.Final.jar.sha1 b/solr/licenses/netty-handler-proxy-4.2.15.Final.jar.sha1
deleted file mode 100644
index cdf1b264bb2e..000000000000
--- a/solr/licenses/netty-handler-proxy-4.2.15.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-31e63e04af11da75793ecbfc126d7691b8771d01
diff --git a/solr/licenses/opentelemetry-exporter-sender-jdk-1.56.0.jar.sha1 b/solr/licenses/opentelemetry-exporter-sender-jdk-1.56.0.jar.sha1
new file mode 100644
index 000000000000..4b0746ab0c9f
--- /dev/null
+++ b/solr/licenses/opentelemetry-exporter-sender-jdk-1.56.0.jar.sha1
@@ -0,0 +1 @@
+a444a2c56f7b40cbde39bc542523a912811b7d97
diff --git a/solr/licenses/opentelemetry-exporter-sender-okhttp-1.56.0.jar.sha1 b/solr/licenses/opentelemetry-exporter-sender-okhttp-1.56.0.jar.sha1
deleted file mode 100644
index 7aaf975e4de2..000000000000
--- a/solr/licenses/opentelemetry-exporter-sender-okhttp-1.56.0.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-5cc7baa0fe03a47f1af52193f480b7d9d8d2a767
diff --git a/solr/licenses/proto-google-common-protos-2.64.1.jar.sha1 b/solr/licenses/proto-google-common-protos-2.64.1.jar.sha1
deleted file mode 100644
index 371f2bdcaaa5..000000000000
--- a/solr/licenses/proto-google-common-protos-2.64.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-a71d9a9867ed792e54e893b8c7864a0ba1b022cf
diff --git a/solr/modules/opentelemetry/build.gradle b/solr/modules/opentelemetry/build.gradle
index b14d3868e41b..53d5e371b6fb 100644
--- a/solr/modules/opentelemetry/build.gradle
+++ b/solr/modules/opentelemetry/build.gradle
@@ -23,7 +23,6 @@ dependencies {
   implementation platform(project(':platform'))
   implementation project(':solr:core')
 
-  implementation platform(libs.netty.bom)
   implementation platform(libs.opentelemetry.bom)
 
   implementation libs.slf4j.api
@@ -32,16 +31,18 @@ dependencies {
   implementation libs.opentelemetry.sdk
   implementation libs.opentelemetry.sdk.metrics
   implementation libs.opentelemetry.sdk.extension.autoconfigure
-  implementation libs.opentelemetry.exporter.otlp
+  implementation(libs.opentelemetry.exporter.otlp) {
+    // Exclude the OkHttp-based sender; we use the JDK HTTP sender to reduce transitive dependencies
+    exclude group: 'io.opentelemetry', module: 'opentelemetry-exporter-sender-okhttp'
+  }
   // End users must recompile with jaeger exporter and/or zipkin exporter if they need these
 
   // NOTE: sdk-autoconfigure needs both opentelemetry-sdk-metrics and opentelemetry-sdk-logs even if we don't use them
 
-  // gRPC transport via netty - since we already ship netty this is more lightweight than netty-shaded
-  runtimeOnly libs.grpc.netty
-  runtimeOnly libs.grpc.protobuf
-  runtimeOnly libs.grpc.stub
-  runtimeOnly libs.grpc.context
+  // JDK HTTP sender (Java 11+) — avoids pulling in OkHttp and gRPC transitive dependencies.
+  // gRPC transport is not supported out of the box; users who need it can add the required
+  // gRPC and OkHttp artifacts to the opentelemetry module's lib directory.
+  runtimeOnly libs.opentelemetry.exporter.sender.jdk
   // See https://issues.apache.org/jira/browse/LOG4J2-3609 due to needing these annotations
   compileOnly libs.apache.tomcat.annotationsapi
 
diff --git a/solr/modules/opentelemetry/gradle.lockfile b/solr/modules/opentelemetry/gradle.lockfile
index 02eab7c04c66..38d774756260 100644
--- a/solr/modules/opentelemetry/gradle.lockfile
+++ b/solr/modules/opentelemetry/gradle.lockfile
@@ -14,12 +14,9 @@ com.fasterxml.jackson:jackson-bom:2.22.0=compileClasspath,jarValidation,runtimeC
 com.fasterxml.woodstox:woodstox-core:7.2.1=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 com.github.ben-manes.caffeine:caffeine:3.2.4=annotationProcessor,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testRuntimeClasspath
 com.github.kevinstern:software-and-algorithms:1.0=annotationProcessor,errorprone,testAnnotationProcessor
-com.google.android:annotations:4.1.1.4=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.google.api.grpc:proto-google-common-protos:2.64.1=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 com.google.auto.service:auto-service-annotations:1.0.1=annotationProcessor,errorprone,testAnnotationProcessor
 com.google.auto.value:auto-value-annotations:1.11.1=annotationProcessor,errorprone,testAnnotationProcessor
 com.google.auto:auto-common:1.2.2=annotationProcessor,errorprone,testAnnotationProcessor
-com.google.code.gson:gson:2.14.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 com.google.errorprone:error_prone_annotation:2.41.0=annotationProcessor,errorprone,testAnnotationProcessor
 com.google.errorprone:error_prone_annotations:2.47.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 com.google.errorprone:error_prone_annotations:2.49.0=annotationProcessor,errorprone,testAnnotationProcessor
@@ -30,14 +27,10 @@ com.google.guava:failureaccess:1.0.3=annotationProcessor,compileClasspath,errorp
 com.google.guava:guava:33.6.0-jre=annotationProcessor,compileClasspath,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testCompileClasspath,testRuntimeClasspath
 com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava=annotationProcessor,compileClasspath,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testCompileClasspath,testRuntimeClasspath
 com.google.j2objc:j2objc-annotations:3.1=annotationProcessor,compileClasspath,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testCompileClasspath,testRuntimeClasspath
-com.google.protobuf:protobuf-java:4.35.1=annotationProcessor,errorprone,jarValidation,runtimeClasspath,runtimeLibs,testAnnotationProcessor,testRuntimeClasspath
+com.google.protobuf:protobuf-java:4.35.1=annotationProcessor,errorprone,testAnnotationProcessor
 com.j256.simplemagic:simplemagic:1.17=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 com.jayway.jsonpath:json-path:3.0.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 com.lmax:disruptor:4.0.0=solrPlatformLibs
-com.squareup.okhttp3:okhttp-jvm:5.4.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.squareup.okhttp3:okhttp:5.4.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.squareup.okio:okio-jvm:3.17.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-com.squareup.okio:okio:3.17.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 com.tdunning:t-digest:3.3=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 commons-cli:commons-cli:1.11.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 commons-codec:commons-codec:1.22.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
@@ -45,23 +38,9 @@ commons-io:commons-io:2.22.0=compileClasspath,jarValidation,runtimeClasspath,run
 io.dropwizard.metrics:metrics-core:4.2.39=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.github.eisop:dataflow-errorprone:3.41.0-eisop1=annotationProcessor,errorprone,testAnnotationProcessor
 io.github.java-diff-utils:java-diff-utils:4.12=annotationProcessor,errorprone,testAnnotationProcessor
-io.grpc:grpc-api:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-context:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-core:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-netty:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-protobuf-lite:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-protobuf:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-stub:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.grpc:grpc-util:1.82.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-bom:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-buffer:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-codec-base:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
-io.netty:netty-codec-compression:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-codec-http2:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-codec-http:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-io.netty:netty-codec-socks:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.netty:netty-common:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
-io.netty:netty-handler-proxy:4.2.15.Final=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.netty:netty-handler:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-resolver:4.2.15.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.netty:netty-tcnative-boringssl-static:2.0.79.Final=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
@@ -84,7 +63,7 @@ io.opentelemetry:opentelemetry-exporter-common:1.56.0=jarValidation,runtimeClass
 io.opentelemetry:opentelemetry-exporter-otlp-common:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-exporter-otlp:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-exporter-prometheus:1.56.0-alpha=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-io.opentelemetry:opentelemetry-exporter-sender-okhttp:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
+io.opentelemetry:opentelemetry-exporter-sender-jdk:1.56.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-common:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-extension-autoconfigure:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,testCompileClasspath,testRuntimeClasspath
@@ -93,7 +72,6 @@ io.opentelemetry:opentelemetry-sdk-metrics:1.56.0=compileClasspath,jarValidation
 io.opentelemetry:opentelemetry-sdk-testing:1.56.0=jarValidation,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk-trace:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
 io.opentelemetry:opentelemetry-sdk:1.56.0=compileClasspath,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testCompileClasspath,testRuntimeClasspath
-io.perfmark:perfmark-api:0.27.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 io.prometheus:prometheus-metrics-exposition-formats:1.1.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.prometheus:prometheus-metrics-model:1.1.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 io.sgr:s2-geometry-library-java:1.0.0=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
@@ -182,8 +160,6 @@ org.glassfish.jersey.media:jersey-media-json-jackson:4.0.2=jarValidation,runtime
 org.glassfish.jersey:jersey-bom:4.0.2=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
 org.hamcrest:hamcrest:3.0=jarValidation,testCompileClasspath,testRuntimeClasspath
 org.javassist:javassist:3.30.2-GA=jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testRuntimeClasspath
-org.jetbrains.kotlin:kotlin-stdlib:2.2.21=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
-org.jetbrains:annotations:26.1.0=jarValidation,runtimeClasspath,runtimeLibs,testRuntimeClasspath
 org.jspecify:jspecify:1.0.0=annotationProcessor,compileClasspath,errorprone,jarValidation,runtimeClasspath,runtimeLibs,solrPlatformLibs,testAnnotationProcessor,testCompileClasspath,testRuntimeClasspath
 org.junit.jupiter:junit-jupiter-api:5.6.2=jarValidation,testRuntimeClasspath
 org.junit.platform:junit-platform-commons:1.6.2=jarValidation,testRuntimeClasspath
diff --git a/solr/modules/opentelemetry/src/java/org/apache/solr/opentelemetry/OtelTracerConfigurator.java b/solr/modules/opentelemetry/src/java/org/apache/solr/opentelemetry/OtelTracerConfigurator.java
index c70acee63c2c..ae1aa625991c 100644
--- a/solr/modules/opentelemetry/src/java/org/apache/solr/opentelemetry/OtelTracerConfigurator.java
+++ b/solr/modules/opentelemetry/src/java/org/apache/solr/opentelemetry/OtelTracerConfigurator.java
@@ -71,7 +71,7 @@ void prepareConfiguration(NamedList<?> args) {
     injectPluginSettingsIfNotConfigured(args);
     setDefaultIfNotConfigured("OTEL_SERVICE_NAME", "solr");
     setDefaultIfNotConfigured("OTEL_TRACES_EXPORTER", "otlp");
-    setDefaultIfNotConfigured("OTEL_EXPORTER_OTLP_PROTOCOL", "grpc");
+    setDefaultIfNotConfigured("OTEL_EXPORTER_OTLP_PROTOCOL", "http/protobuf");
     setDefaultIfNotConfigured("OTEL_TRACES_SAMPLER", "parentbased_always_on");
     setDefaultIfNotConfigured("OTEL_PROPAGATORS", "tracecontext,baggage");
     if (EnvUtils.getProperty("host") != null) {
diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
index fb4cdb050cc3..116f5bfeb2a5 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
@@ -18,7 +18,7 @@
 
 Solr includes a general tracing framework based on OpenTracing that can be used to trace the lifecycle of a request for performance monitoring.
 
-Tracing data can be configured to send to various backends, either directly or via an agent. Solr can send traces directly in OTLP/gRPC format. You can support many other destinations and cloud providers by installing an agent on each node and sending traces to localhost.
+Tracing data can be configured to send to various backends, either directly or via an agent. Solr can send traces directly in OTLP/HTTP format. You can support many other destinations and cloud providers by installing an agent on each node and sending traces to localhost.
 
 A sampled distributed tracing query request displayed in Jaeger UI looks like this:
 
@@ -39,7 +39,7 @@ This plugin can be disabled by setting the `solr.tracing.always.on.enabled` syst
 The `TracerConfigurator` is a class used to provide an instance of `io.opentracing.Tracer` based on configuration in `solr.xml`.
 These are pluggable, and each plugin is shipped as a xref:configuration-guide:solr-modules.adoc[Solr Module]:
 
-**opentelemetry**: The `opentelemetry` module supports OTLP over gRPC or HTTP.
+**opentelemetry**: The `opentelemetry` module supports OTLP over HTTP.
 
 A setup of a `TracerConfigurator` in `solr.xml` looks like this:
 
@@ -70,24 +70,27 @@ Enable the module with either system property `-Dsolr.modules=opentelemetry` or
 
 The tracer can be configured through environment variables or Java system properties, see https://opentelemetry.io/docs/reference/specification/sdk-environment-variables/[OTEL SDK Environment Variables] and https://github.com/open-telemetry/opentelemetry-java/blob/v{dep-version-opentelemetry}/sdk-extensions/autoconfigure/README.md[Java SDK Autoconfigure].
 
-The default configuration will ship traces to a collector running on localhost, using https://opentelemetry.io/docs/reference/specification/protocol/[OTLP] over https://grpc.io[gRPC], and will propagate trace IDs using https://www.w3.org/TR/trace-context/[W3C TraceContext]. Here are the environment settings that are enabled by default:
+The default configuration will ship traces to a collector running on localhost, using https://opentelemetry.io/docs/reference/specification/protocol/[OTLP] over HTTP (Protobuf), and will propagate trace IDs using https://www.w3.org/TR/trace-context/[W3C TraceContext]. Here are the environment settings that are enabled by default:
 
 [source,bash]
 ----
 OTEL_SDK_DISABLED=false
 OTEL_SERVICE_NAME=solr
 OTEL_TRACES_EXPORTER=otlp
-OTEL_EXPORTER_OTLP_PROTOCOL=grpc
-OTEL_EXPORTER_OTLP_ENDPOINT=localhost:4317
+OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
+OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318
 OTEL_TRACES_SAMPLER=parentbased_always_on
 OTEL_PROPAGATORS=tracecontext,baggage
 ----
 
+NOTE: gRPC transport is not supported out of the box.
+To use gRPC, you must add the required gRPC, OkHttp, and Protobuf jars to the `opentelemetry` module's lib directory and set `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
+
 Say you want to send traces to a remote https://opentelemetry.io/docs/collector/[OTEL Collector], with 10% sampling. That could be done with this configuration:
 
 [source,bash]
 ----
-OTEL_EXPORTER_OTLP_ENDPOINT=my-remote-collector:4317
+OTEL_EXPORTER_OTLP_ENDPOINT=http://my-remote-collector:4318
 OTEL_TRACES_SAMPLER=parentbased_traceidratio
 OTEL_TRACES_SAMPLER_ARG=0.1
 ----
@@ -96,7 +99,7 @@ An equivalent configuration using system properties would be:
 
 [source,bash]
 ----
-SOLR_OPTS=-Dotel.exporter.otlp.endpoint=my-remote-collector:4317 -Dotel.traces.sampler=parentbased_traceidratio -Dotel.traces.sampler.arg=0.1
+SOLR_OPTS=-Dotel.exporter.otlp.endpoint=http://my-remote-collector:4318 -Dotel.traces.sampler=parentbased_traceidratio -Dotel.traces.sampler.arg=0.1
 ----
 
 To add custom tags to the trace, use `OTEL_RESOURCE_ATTRIBUTES`:
diff --git a/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc b/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
index 762c5e440d80..39ed75d4a1a9 100644
--- a/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
+++ b/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
@@ -390,6 +390,13 @@ A new feature vector cache was added that is used not only for feature logging b
 
 The new OTEL based metric system introduced in 10.0 is considered BETA, and some breaking changes are to be expected in this and coming minor releases.
 
+==== OpenTelemetry Tracing Transport Changed to HTTP
+
+The `opentelemetry` module now uses the JDK HTTP sender (`opentelemetry-exporter-sender-jdk`) instead of OkHttp (`opentelemetry-exporter-sender-okhttp`) to reduce transitive dependencies.
+As a result, gRPC transport is no longer supported out of the box, and the default export protocol has changed from `grpc` to `http/protobuf` (OTLP port `4318` instead of `4317`).
+
+Users who relied on gRPC transport can restore it by adding the required gRPC, OkHttp, and Protobuf jars to the `opentelemetry` module's lib directory and setting `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
+
 ==== OTLP Metric Names Changed to Dot-Separated Format
 
 *Breaking change for OTLP consumers.*

From 83826f03b64d403381199c97dbe986e55a04afa6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 18 Jul 2026 19:00:15 +0000
Subject: [PATCH 2/7] SOLR-18310: Keep libs.versions.toml sorted

---
 gradle/libs.versions.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 195905469d91..fe7d4d6d756a 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -486,8 +486,8 @@ opentelemetry-api = { module = "io.opentelemetry:opentelemetry-api", version.ref
 opentelemetry-bom = { module = "io.opentelemetry:opentelemetry-bom", version.ref = "opentelemetry" }
 opentelemetry-context = { module = "io.opentelemetry:opentelemetry-context", version.ref = "opentelemetry" }
 opentelemetry-exporter-otlp = { module = "io.opentelemetry:opentelemetry-exporter-otlp", version.ref = "opentelemetry" }
-opentelemetry-exporter-sender-jdk = { module = "io.opentelemetry:opentelemetry-exporter-sender-jdk", version.ref = "opentelemetry" }
 opentelemetry-exporter-prometheus = { module = "io.opentelemetry:opentelemetry-exporter-prometheus", version.ref = "opentelemetry-prometheus" }
+opentelemetry-exporter-sender-jdk = { module = "io.opentelemetry:opentelemetry-exporter-sender-jdk", version.ref = "opentelemetry" }
 opentelemetry-runtime-telemetry = { module = "io.opentelemetry.instrumentation:opentelemetry-runtime-telemetry-java17", version.ref = "opentelemetry-runtime-telemetry" }
 opentelemetry-sdk = { module = "io.opentelemetry:opentelemetry-sdk", version.ref = "opentelemetry" }
 opentelemetry-sdk-extension-autoconfigure = { module = "io.opentelemetry:opentelemetry-sdk-extension-autoconfigure", version.ref = "opentelemetry" }

From 6e66c95da2bf4210b755616887e3689f17c7b19b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 18 Jul 2026 19:08:50 +0000
Subject: [PATCH 3/7] SOLR-18310: Fix changelog entry and refresh lockfiles

---
 .../unreleased/SOLR-18310-otel-jdk-sender.yml | 11 +++++++
 .../update-opentelemetry-exporter.yml         | 33 -------------------
 2 files changed, 11 insertions(+), 33 deletions(-)
 create mode 100644 changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
 delete mode 100644 changelog/unreleased/update-opentelemetry-exporter.yml

diff --git a/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml b/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
new file mode 100644
index 000000000000..4d04a3eac3f4
--- /dev/null
+++ b/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
@@ -0,0 +1,11 @@
+title: >
+  Switch the opentelemetry module from OkHttp to the JDK HTTP sender to reduce transitive dependencies.
+  The default OTLP export protocol changed from gRPC (port 4317) to HTTP/Protobuf (port 4318).
+  gRPC transport is no longer bundled; users who need it can add the required gRPC and OkHttp jars
+  to the opentelemetry module's lib directory.
+type: dependency_update
+authors:
+  - name: David Smiley
+links:
+  - name: SOLR-18310
+    url: https://issues.apache.org/jira/browse/SOLR-18310
diff --git a/changelog/unreleased/update-opentelemetry-exporter.yml b/changelog/unreleased/update-opentelemetry-exporter.yml
deleted file mode 100644
index c459197a9e44..000000000000
--- a/changelog/unreleased/update-opentelemetry-exporter.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-# (DELETE ALL COMMENTS UP HERE AFTER FILLING THIS IN
-
-# See https://github.com/apache/solr/blob/main/dev-docs/changelog.adoc
-
-# If the change is minor, don't bother adding a changelog entry.
-# For `other` type entries, the threshold to bother with a changelog entry should be even higher.
-
-# title:
-#  * The audience is end-users and administrators, not committers.
-#  * Be short and focused on the user impact.  Multiple sentences is fine!
-#  * For technical/geeky details, prefer the commit message instead of changelog.
-#  * Reference JIRA issues like `SOLR-12345`, or if no JIRA but have a GitHub PR then `PR#12345`.
-
-# type:
-#  `added` for new features/improvements, opt-in by the user typically documented in the ref guide
-#  `changed` for improvements; not opt-in
-#  `fixed` for improvements that are deemed to have fixed buggy behavior
-#  `deprecated` for marking things deprecated
-#  `removed` for code removed
-#  `dependency_update` for updates to dependencies
-#  `other` for anything else, like large/significant refactorings, build changes,
-#    test infrastructure, or documentation.
-#    Most such changes are too small/minor to bother with a changelog entry.
-
-title: >
-  SOLR-18310: The opentelemetry module now uses the JDK HTTP sender instead of OkHttp, reducing
-  transitive dependencies. The default OTLP export protocol has changed from gRPC (port 4317) to
-  HTTP/Protobuf (port 4318). gRPC transport is no longer supported out of the box; users who need
-  it can add the required gRPC, OkHttp, and Protobuf jars to the opentelemetry module's lib directory.
-type: dependency_update
-authors:
-  - name: copilot-swe-agent[bot]
-

From bcb434d17f93dced84717ce30ef5b5dbe1a6c310 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 18 Jul 2026 19:59:54 +0000
Subject: [PATCH 4/7] SOLR-18310: Improve gRPC restore note in
 distributed-tracing.adoc with Maven Central link

---
 .../modules/deployment-guide/pages/distributed-tracing.adoc    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
index 116f5bfeb2a5..3e1c6d1bb2fe 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
@@ -84,7 +84,8 @@ OTEL_PROPAGATORS=tracecontext,baggage
 ----
 
 NOTE: gRPC transport is not supported out of the box.
-To use gRPC, you must add the required gRPC, OkHttp, and Protobuf jars to the `opentelemetry` module's lib directory and set `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
+To use gRPC, add the required gRPC, OkHttp, and Protobuf JARs to the `opentelemetry` module's lib directory and set `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
+Look up the full list of runtime JARs needed at https://central.sonatype.com/artifact/io.opentelemetry/opentelemetry-exporter-sender-okhttp/1.56.0/dependencies[opentelemetry-exporter-sender-okhttp on Maven Central] (replace `1.56.0` with the OpenTelemetry version bundled in your Solr release).
 
 Say you want to send traces to a remote https://opentelemetry.io/docs/collector/[OTEL Collector], with 10% sampling. That could be done with this configuration:
 

From 9151d335c651a23aae4a424b9e8a6ee17ad1016f Mon Sep 17 00:00:00 2001
From: David Smiley <dsmiley@apache.org>
Date: Mon, 20 Jul 2026 01:09:23 -0400
Subject: [PATCH 5/7] tweaks

---
 changelog/unreleased/SOLR-18310-otel-jdk-sender.yml   |  6 ++----
 solr/modules/opentelemetry/build.gradle               |  9 ++-------
 solr/server/etc/security.policy                       |  3 +++
 .../deployment-guide/pages/distributed-tracing.adoc   | 11 +++++++----
 .../upgrade-notes/pages/major-changes-in-solr-10.adoc |  8 ++++----
 5 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml b/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
index 4d04a3eac3f4..6a0d31c28f06 100644
--- a/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
+++ b/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
@@ -1,8 +1,6 @@
 title: >
-  Switch the opentelemetry module from OkHttp to the JDK HTTP sender to reduce transitive dependencies.
-  The default OTLP export protocol changed from gRPC (port 4317) to HTTP/Protobuf (port 4318).
-  gRPC transport is no longer bundled; users who need it can add the required gRPC and OkHttp jars
-  to the opentelemetry module's lib directory.
+  Removed OkHttp, gRPC, and Netty jars from the opentelemetry module.  The OTLP/http protocol still
+  works but no longer uses additional dependencies.
 type: dependency_update
 authors:
   - name: David Smiley
diff --git a/solr/modules/opentelemetry/build.gradle b/solr/modules/opentelemetry/build.gradle
index 53d5e371b6fb..49877fbcd93c 100644
--- a/solr/modules/opentelemetry/build.gradle
+++ b/solr/modules/opentelemetry/build.gradle
@@ -32,16 +32,11 @@ dependencies {
   implementation libs.opentelemetry.sdk.metrics
   implementation libs.opentelemetry.sdk.extension.autoconfigure
   implementation(libs.opentelemetry.exporter.otlp) {
-    // Exclude the OkHttp-based sender; we use the JDK HTTP sender to reduce transitive dependencies
+    // Exclude the OkHttp-based sender; we use the JDK HTTP sender instead
     exclude group: 'io.opentelemetry', module: 'opentelemetry-exporter-sender-okhttp'
   }
-  // End users must recompile with jaeger exporter and/or zipkin exporter if they need these
 
-  // NOTE: sdk-autoconfigure needs both opentelemetry-sdk-metrics and opentelemetry-sdk-logs even if we don't use them
-
-  // JDK HTTP sender (Java 11+) — avoids pulling in OkHttp and gRPC transitive dependencies.
-  // gRPC transport is not supported out of the box; users who need it can add the required
-  // gRPC and OkHttp artifacts to the opentelemetry module's lib directory.
+  // OTLP HTTP sender that requires no additional dependencies.
   runtimeOnly libs.opentelemetry.exporter.sender.jdk
   // See https://issues.apache.org/jira/browse/LOG4J2-3609 due to needing these annotations
   compileOnly libs.apache.tomcat.annotationsapi
diff --git a/solr/server/etc/security.policy b/solr/server/etc/security.policy
index f932cc0b461c..2dd03af0be24 100644
--- a/solr/server/etc/security.policy
+++ b/solr/server/etc/security.policy
@@ -215,6 +215,9 @@ grant {
 
   // expanded to a wildcard if set, allows all networking everywhere
   permission java.net.SocketPermission "${solr.internal.network.permission}", "accept,listen,connect,resolve";
+  // java.net.http.HttpClient requires URLPermission separately from SocketPermission above.
+  permission java.net.URLPermission "http://${solr.internal.network.permission}:*/-", "*:*";
+  permission java.net.URLPermission "https://${solr.internal.network.permission}:*/-", "*:*";
 
   // CUDA for GPU module (cuVS)
   permission java.lang.RuntimePermission "loadLibrary.cudart";
diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
index 3e1c6d1bb2fe..fb60329ee036 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/distributed-tracing.adoc
@@ -18,7 +18,10 @@
 
 Solr includes a general tracing framework based on OpenTracing that can be used to trace the lifecycle of a request for performance monitoring.
 
-Tracing data can be configured to send to various backends, either directly or via an agent. Solr can send traces directly in OTLP/HTTP format. You can support many other destinations and cloud providers by installing an agent on each node and sending traces to localhost.
+Tracing data can be configured to send to various backends, either directly or via an agent.
+Solr can send traces directly in OTLP/HTTP format with the opentelemetry module, out-of-the-box.
+Other protocols, destinations and cloud providers may be supported.
+For example, gRPC can be supported by adding more JARs and tweaking configuration.
 
 A sampled distributed tracing query request displayed in Jaeger UI looks like this:
 
@@ -55,7 +58,8 @@ By doing this, some backends like DataDog are supported out of the box since htt
 
 == Open Telemetry Module
 
-This module brings support for the industry standard https://opentelemetry.io[OpenTelemetry] (or short "OTEL") tracing, and exposes a tracer configurator that can be enabled in the `<tracerConfig>` tag of `solr.xml` as follows:
+This module brings support for the industry standard https://opentelemetry.io[OpenTelemetry] ("OTEL").
+OTEL is broader than tracing, but nonetheless, Solr's focal configuration element for it in Solr is `<tracerConfig>` in `solr.xml` as follows:
 
 [source,xml]
 ----
@@ -84,8 +88,7 @@ OTEL_PROPAGATORS=tracecontext,baggage
 ----
 
 NOTE: gRPC transport is not supported out of the box.
-To use gRPC, add the required gRPC, OkHttp, and Protobuf JARs to the `opentelemetry` module's lib directory and set `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
-Look up the full list of runtime JARs needed at https://central.sonatype.com/artifact/io.opentelemetry/opentelemetry-exporter-sender-okhttp/1.56.0/dependencies[opentelemetry-exporter-sender-okhttp on Maven Central] (replace `1.56.0` with the OpenTelemetry version bundled in your Solr release).
+To use gRPC, add the required gRPC and Netty JARs to the `opentelemetry` module's lib directory and set `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
 
 Say you want to send traces to a remote https://opentelemetry.io/docs/collector/[OTEL Collector], with 10% sampling. That could be done with this configuration:
 
diff --git a/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc b/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
index 39ed75d4a1a9..e2f3c2bf1067 100644
--- a/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
+++ b/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
@@ -390,12 +390,12 @@ A new feature vector cache was added that is used not only for feature logging b
 
 The new OTEL based metric system introduced in 10.0 is considered BETA, and some breaking changes are to be expected in this and coming minor releases.
 
-==== OpenTelemetry Tracing Transport Changed to HTTP
+==== OTLP protocols
 
-The `opentelemetry` module now uses the JDK HTTP sender (`opentelemetry-exporter-sender-jdk`) instead of OkHttp (`opentelemetry-exporter-sender-okhttp`) to reduce transitive dependencies.
-As a result, gRPC transport is no longer supported out of the box, and the default export protocol has changed from `grpc` to `http/protobuf` (OTLP port `4318` instead of `4317`).
+The `opentelemetry` module no longer includes some dependencies, dropping gRPC support out-of-the-box.
+The default export protocol has changed from `grpc` to `http/protobuf` (OTLP port `4318` instead of `4317`).
 
-Users who relied on gRPC transport can restore it by adding the required gRPC, OkHttp, and Protobuf jars to the `opentelemetry` module's lib directory and setting `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
+Use of gRPC can be restored by adding the required gRPC & Netty jars to the `opentelemetry` module's lib directory and setting `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
 
 ==== OTLP Metric Names Changed to Dot-Separated Format
 

From 29ba510444e7da9e0f629c5dd90f5dc3bd4ea5cf Mon Sep 17 00:00:00 2001
From: David Smiley <dsmiley@apache.org>
Date: Mon, 20 Jul 2026 09:25:24 -0400
Subject: [PATCH 6/7] tweak wording

---
 changelog/unreleased/SOLR-18310-otel-jdk-sender.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml b/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
index 6a0d31c28f06..93a8000d999f 100644
--- a/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
+++ b/changelog/unreleased/SOLR-18310-otel-jdk-sender.yml
@@ -1,6 +1,6 @@
 title: >
-  Removed OkHttp, gRPC, and Netty jars from the opentelemetry module.  The OTLP/http protocol still
-  works but no longer uses additional dependencies.
+  opentelemetry: the default OTLP sender is now http/protobuf port 4318 and with fewer/no JARs to do so.
+  JARs for others like gRPC have been removed but users can add as they need.
 type: dependency_update
 authors:
   - name: David Smiley

From a7bc70147b71396e6746e461406ef4e824a1272e Mon Sep 17 00:00:00 2001
From: David Smiley <dsmiley@apache.org>
Date: Mon, 20 Jul 2026 16:19:42 -0400
Subject: [PATCH 7/7] improve docs

---
 .../modules/deployment-guide/pages/metrics-reporting.adoc   | 6 ++++--
 .../upgrade-notes/pages/major-changes-in-solr-10.adoc       | 5 +++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/solr/solr-ref-guide/modules/deployment-guide/pages/metrics-reporting.adoc b/solr/solr-ref-guide/modules/deployment-guide/pages/metrics-reporting.adoc
index 15a2d592f87d..adab80215801 100644
--- a/solr/solr-ref-guide/modules/deployment-guide/pages/metrics-reporting.adoc
+++ b/solr/solr-ref-guide/modules/deployment-guide/pages/metrics-reporting.adoc
@@ -312,7 +312,7 @@ http://localhost:8983/api/metrics?name=solr_core_index_size_bytes&collection=foo
 
 == OTLP
 
-For users who do not use or support pulling metrics in Prometheus format with the `/metrics` API, Solr also supports pushing metrics natively with https://opentelemetry.io/docs/specs/otlp/[OTLP], which is a vendor-agnostic protocol for pushing metrics via gRPC or HTTP.
+For users who do not use or support pulling metrics in Prometheus format with the `/metrics` API, Solr also supports pushing metrics natively with https://opentelemetry.io/docs/specs/otlp/[OTLP], which is a vendor-agnostic protocol for pushing metrics.
 
 OTLP is widely supported by many tools, vendors, and pipelines. See the OpenTelemetry https://opentelemetry.io/ecosystem/vendors/[vendors list] for more details on available and compatible options.
 
@@ -341,11 +341,13 @@ Boolean value to enable or disable the OTLP metrics exporter.
 +
 [%autowidth,frame=none]
 |===
-|Optional |Default: grpc
+|Optional |Default: http
 |===
 +
 OTLP protocol to use for pushing metrics. Available options are `grpc`, `http`, or `none` (disabled).
 
+NOTE: gRPC is not supported out of the box. To use it, add the required gRPC and Netty JARs to the `opentelemetry` module's lib directory.
+
 `solr.metrics.otlpExporterInterval`::
 +
 [%autowidth,frame=none]
diff --git a/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc b/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
index e2f3c2bf1067..803a21da56d8 100644
--- a/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
+++ b/solr/solr-ref-guide/modules/upgrade-notes/pages/major-changes-in-solr-10.adoc
@@ -393,9 +393,10 @@ The new OTEL based metric system introduced in 10.0 is considered BETA, and some
 ==== OTLP protocols
 
 The `opentelemetry` module no longer includes some dependencies, dropping gRPC support out-of-the-box.
-The default export protocol has changed from `grpc` to `http/protobuf` (OTLP port `4318` instead of `4317`).
+The default export protocol for tracing has changed from `grpc` to `http/protobuf` (OTLP port `4318` instead of `4317`).
+The default for the separate OTLP metrics exporter's `solr.metrics.otlpExporterProtocol` has likewise changed from `grpc` to `http`.
 
-Use of gRPC can be restored by adding the required gRPC & Netty jars to the `opentelemetry` module's lib directory and setting `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`.
+Use of gRPC can be restored by adding the required gRPC & Netty jars to the `opentelemetry` module's lib directory, and setting `OTEL_EXPORTER_OTLP_PROTOCOL=grpc` (tracing) and/or `solr.metrics.otlpExporterProtocol=grpc` (metrics) as needed.
 
 ==== OTLP Metric Names Changed to Dot-Separated Format