Replace DataCarrier with BatchQueue for metrics pipeline

[wu-sheng]

New feature: library-batch-queue module

• Update the documentation to include this new feature.
• Tests(including UT, IT, E2E) are added to verify the new feature.

A partitioned, self-draining queue with type-based dispatch. Designed to replace DataCarrier in high-fan-out scenarios.

Key features:

• One queue per concern, many types per queue. OAL + MAL metric types share unified queues instead of separate pools. Individual metric types register handlers; the queue groups drained items by class and dispatches to matching handlers.
• Adaptive partitioning. Partition count grows automatically with addHandler() calls (~330 partitions for typical OAL+MAL workload on 8 threads), giving each metric type its own lock-free ArrayBlockingQueue.
• Idle backoff. Drain loops double their sleep interval when idle (minIdleMs * 2^count, capped at maxIdleMs), resetting on first non-empty drain. No busy-waiting.
• Shared scheduler with ref-counting. Low-throughput queues (exporters) share one thread pool; the pool auto-shuts down when the last queue releases it.
• Hardware-aware thread sizing. ThreadPolicy resolves thread count at runtime: cpuCores(1.0), cpuCoresWithBase(1, 0.25), or fixed(N).
• Throughput-weighted drain rebalancing. DrainBalancer.throughputWeighted() periodically reassigns partitions to equalize per-thread load when metric types have skewed throughput. Enabled for L1 and L2 with 10-second interval.

Adaptive partition mode (PartitionPolicy.adaptive())

Used by L1 aggregation, L2 persistence, and TopN queues. The partition count grows as metric type handlers are registered via addHandler(), rather than being fixed at construction time.

The algorithm uses a threshold = threadCount * multiplier (default multiplier = 25). With 8 drain threads the threshold is 200:

• Below threshold (handlers ≤ 200): one partition per handler (1:1 mapping). Each metric type gets its own dedicated ArrayBlockingQueue, eliminating contention between types.
• Above threshold (handlers > 200): excess handlers share partitions at 1:2 ratio: threshold + (handlerCount - threshold) / 2. This avoids unbounded partition growth while keeping most types isolated.

Examples with 8 threads (threshold = 200):

Registered handlers	Partitions	Ratio
0 (initial)	8	= threadCount
100	100	1:1
200	200	1:1, at threshold
500	350	200 + 300/2
1000	600	200 + 800/2

In practice, a typical OAL + MAL deployment has ~460 metric types, producing ~330 partitions on 8 threads (threshold 200, so 200 + (460-200)/2 = 330).

Thread policies

ThreadPolicy.cpuCores(multiplier) — Threads = round(multiplier × availableProcessors()), minimum 1. Scales with hardware: same config runs 8 threads on 8-core, 16 on 16-core.

Used by L1 aggregation with cpuCores(1.0) — one thread per core. L1 is CPU-bound (merging metrics in memory) and benefits from maximum parallelism.

ThreadPolicy.cpuCoresWithBase(base, multiplier) — Threads = base + round(multiplier × availableProcessors()), minimum 1. Provides a guaranteed minimum (base) plus hardware-proportional scaling.

Used by L2 persistence with cpuCoresWithBase(1, 0.25) — 1 + ¼ of cores. On 8-core = 3 threads, on 16-core = 5 threads, on 24-core = 7 threads. L2 is I/O-bound (writing to storage); fewer threads are needed but at least 1 is always guaranteed even on minimal hardware.

ThreadPolicy.fixed(N) — Exactly N threads regardless of hardware.

Used by TopN (1 thread), exporters (1 thread each), gRPC remote client (1 thread per peer), JDBC batch (configurable, default 4).

Improve the performance of metrics aggregation and persistence pipeline

• Add a benchmark for the improvement.
• The benchmark result.
• Links/URLs to the theory proof or discussion articles/blogs: LPT (Longest Processing Time) heuristic — see Wikipedia: Multiprocessor scheduling.

Thread count reduction from 36 to 15 on an 8-core machine (gRPC remote client excluded — unchanged 1 thread per peer).

Queue	Old threads	New threads	New policy
L1 Aggregation (OAL+MAL unified)	26	8	cpuCores(1.0)
L2 Persistence (OAL+MAL unified)	3	3	cpuCoresWithBase(1, 0.25)
TopN Persistence	4	1	fixed(1)
Exporters (gRPC/Kafka)	3	3	fixed(1) each
Total	36	15

Throughput: BatchQueue vs DataCarrier (ideal — uniform load across types)

Benchmark config: 32 producers, fixed(8) drain threads, IF_POSSIBLE strategy.
Metric types simulated with 2000 distinct classes, each carrying a boxed Long payload.

Partition strategy	500 types	1000 types	2000 types
DataCarrier baseline	33.4M	37.6M	38.0M
BatchQueue adaptive	45.7M (+37%)	50.5M (+34%)	64.0M (+68%)
BatchQueue 1:1	51.3M (+53%)	61.2M (+63%)	75.7M (+99%)

Throughput: static vs rebalanced (OAL/MAL skewed load)

Real OAL/MAL workloads have highly skewed entity counts — endpoint-scoped metrics (~24 entities) dominate
over service-scoped (~4 entities) and MAL (~1 entity). Static round-robin partition assignment creates
thread imbalance.

DrainBalancer.throughputWeighted() periodically snapshots per-partition throughput counters,
sorts partitions by load descending, and assigns each to the least-loaded thread (LPT heuristic).
A two-phase handoff (revoke → cycle-count fence → assign) prevents concurrent handler invocations
during reassignment. Enabled for L1 aggregation and L2 persistence with a 10-second rebalance interval.

Benchmark config: 4 drain threads, 16 producers, 100 types with entity-count-driven skew, 500 LCG iterations per item.

                    Static          Rebalanced
  Throughput:    7,211,794         8,729,310  items/sec
  Load ratio:       1.30x             1.04x  (max/min thread)
  Improvement:                       +21.0%

Stability over 20 seconds (sampled every 2s after initial rebalance):

  Interval    Throughput      Ratio
   0- 2s     8,915,955       1.00x
   2- 4s     8,956,595       1.01x
   4- 6s     8,934,778       1.00x
   6- 8s     8,838,461       1.01x
   8-10s     8,887,092       1.00x
  10-12s     8,844,614       1.00x
  12-14s     8,877,651       1.00x
  14-16s     8,851,595       1.01x
  16-18s     8,639,045       1.01x
  18-20s     8,708,210       1.01x
  Stable: YES (avg ratio 1.01x)

Other changes

• Add named ThreadFactory to all anonymous Executors pool threads for easier thread dump analysis.
• Remove library-datacarrier-queue module. All usages replaced by library-batch-queue.

Commits

#	Commit	Description
1	Add library-batch-queue module	Core queue implementation: BatchQueue, BatchQueueManager, BatchQueueConfig, ThreadPolicy, PartitionPolicy, PartitionSelector, BufferStrategy, HandlerConsumer, BatchQueueStats, QueueErrorHandler. Includes unit tests, throughput benchmarks, and DataCarrier comparison benchmarks.
2	Replace DataCarrier with BatchQueue	Migrate L1 aggregation, L2 persistence, TopN, all three exporters (gRPC metrics, Kafka trace, Kafka log), gRPC remote client, and JDBC batch DAO from DataCarrier to BatchQueue. Unify OAL+MAL into shared queues. Remove library-datacarrier-queue module. Fix RemoteClientManagerTestCase for static BatchQueueManager registry cleanup.
3	Add CLAUDE.md for library-batch-queue	Module documentation: design principles, architecture, dispatch modes, scheduler modes, key classes, drain rebalancing, and per-queue usage across the codebase.
4	Add named ThreadFactory	Replace anonymous pool-N-thread-M thread names with descriptive names across all Executors.newXxx() calls in the OAP server for easier thread dump analysis.
5	Add throughput-weighted drain rebalancing	DrainBalancer interface with ThroughputWeightedBalancer implementation (LPT heuristic, two-phase handoff, cycle-count fencing). Enabled for L1 aggregation and L2 persistence queues with 10-second rebalance interval. Includes equals/hashCode on ThreadPolicy, duplicate queue name detection in BatchQueueManager.

• Update the CHANGES log.

[Copilot]

Pull request overview

This PR introduces a new library-batch-queue module and migrates OAP server internal pipelines from DataCarrier to BatchQueue, aiming to reduce thread counts, unify OAL/MAL queues, and improve observability via named executor threads. It also updates OTel rules and Grafana/So11y dashboards to match the new queue metrics dimensions and removes the legacy library-datacarrier-queue module.

Changes:

• Add library-batch-queue (partitioned, self-draining queue) and replace DataCarrier usages across aggregation/persistence/TopN/exporters/remote client.
• Name anonymous executor threads across the OAP server for easier thread-dump analysis.
• Update telemetry rules and dashboards for the new queue metrics tags/dimensions; remove library-datacarrier-queue and related tests.

Reviewed changes

Copilot reviewed 98 out of 98 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/common/dao/JDBCBatchDAO.java	Switch JDBC async batching from DataCarrier to BatchQueue.
oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/pom.xml	Replace datacarrier dependency with library-batch-queue.
oap-server/server-storage-plugin/storage-banyandb-plugin/pom.xml	Remove unused library-datacarrier-queue dependency.
oap-server/server-starter/src/main/resources/ui-initialized-templates/so11y_oap/so11y-instance.json	Update So11y dashboard expressions/titles for unified queues and new labels.
oap-server/server-starter/src/main/resources/otel-rules/oap.yaml	Update OTel aggregation rule dimensions (remove kind, add slot).
oap-server/server-library/pom.xml	Remove library-datacarrier-queue, add library-batch-queue module.
oap-server/server-library/library-util/src/test/java/org/apache/skywalking/oap/server/library/util/benchmark/StringFormatGroupBenchmark.java	Add benchmark-style test for StringFormatGroup.
oap-server/server-library/library-util/src/main/java/org/apache/skywalking/oap/server/library/util/MultipleFilesChangeMonitor.java	Name the scheduled executor thread for file monitoring.
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/partition/SimpleRollingPartitionerTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/partition/ProducerThreadPartitionerTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/SampleConsumer.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumerTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumerPoolFactoryTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumeDriverTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/SampleData.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/EnvUtilTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/test/java/org/apache/skywalking/oap/server/library/datacarrier/DataCarrierTest.java	Remove datacarrier tests (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/partition/SimpleRollingPartitioner.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/partition/ProducerThreadPartitioner.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/partition/IDataPartitioner.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/MultipleChannelsConsumer.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/IDriver.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumerThread.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumerPoolFactory.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumerPool.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/ConsumeDriver.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/consumer/BulkConsumePool.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/common/AtomicRangeInteger.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/buffer/QueueBuffer.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/buffer/Channels.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/buffer/ArrayBlockingQueueBuffer.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/EnvUtil.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-datacarrier-queue/src/main/java/org/apache/skywalking/oap/server/library/datacarrier/DataCarrier.java	Remove datacarrier implementation (module removal).
oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/grpc/GRPCClient.java	Name the health-check scheduled executor thread.
oap-server/server-library/library-batch-queue/src/test/resources/log4j2-test.xml	Add log4j2 test config for the new module tests.
oap-server/server-library/library-batch-queue/src/test/java/org/apache/skywalking/oap/server/library/batchqueue/ThreadPolicyTest.java	Add unit tests for ThreadPolicy.
oap-server/server-library/library-batch-queue/src/test/java/org/apache/skywalking/oap/server/library/batchqueue/PartitionPolicyTest.java	Add unit tests for PartitionPolicy.
oap-server/server-library/library-batch-queue/src/test/java/org/apache/skywalking/oap/server/library/batchqueue/BenchmarkMetricTypes.java	Add benchmark helper for dispatch testing.
oap-server/server-library/library-batch-queue/src/test/java/org/apache/skywalking/oap/server/library/batchqueue/BatchQueueManagerTest.java	Add tests for queue registry/shared scheduler semantics.
oap-server/server-library/library-batch-queue/src/test/java/org/apache/skywalking/oap/server/library/batchqueue/BatchQueueConfigTest.java	Add tests for config validation/defaults.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/ThreadPolicy.java	Introduce thread-count policy abstraction.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/QueueErrorHandler.java	Add error handler functional interface in batchqueue package.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/PartitionSelector.java	Add partition-selection strategy API.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/PartitionPolicy.java	Add partition-count policy abstraction (fixed/threadMultiply/adaptive).
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/HandlerConsumer.java	Define handler consumer contract and idle hook.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/BufferStrategy.java	Define buffer backpressure/drop strategies.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/BatchQueueStats.java	Add queue usage snapshot/top-N partition reporting.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/BatchQueueManager.java	Add global queue registry + shared scheduler ref-counting.
oap-server/server-library/library-batch-queue/src/main/java/org/apache/skywalking/oap/server/library/batchqueue/BatchQueueConfig.java	Add queue config builder + validation.
oap-server/server-library/library-batch-queue/pom.xml	Rename module artifact + add test dependencies.
oap-server/server-library/library-batch-queue/DESIGN.md	Document drain rebalancing design.
oap-server/server-library/library-batch-queue/CLAUDE.md	Add module-specific assistant documentation.
oap-server/server-library/library-banyandb-client/src/main/java/org/apache/skywalking/library/banyandb/v1/client/grpc/channel/ChannelManager.java	Name the BanyanDB channel manager scheduler thread.
oap-server/server-health-checker/src/main/java/org/apache/skywalking/oap/server/health/checker/provider/HealthCheckerProvider.java	Name the health checker scheduler thread.
oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClientTestCase.java	Update tests for new GRPCRemoteClient ctor signature.
oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClientRealClient.java	Update tests for new GRPCRemoteClient ctor signature.
oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/benchmark/RegexVSQuickMatchBenchmark.java	Add benchmark-style tests for endpoint grouping performance.
oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/benchmark/EndpointGrouping4OpenapiBenchmark.java	Add benchmark-style tests for OpenAPI grouping reader/formatter.
oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/benchmark/EBPFProfilingAnalyzerBenchmark.java	Add benchmark-style tests for EBPF profiling analyzer.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/watermark/WatermarkWatcher.java	Name the watermark watcher scheduler thread.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/ttl/DataTTLKeeperTimer.java	Name the TTL keeper scheduler thread.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/PersistenceTimer.java	Name persistence timer threads (scheduler + prepare pool).
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/RemoteClientManager.java	Name remote client manager scheduler thread; update GRPCRemoteClient ctor usage.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClient.java	Replace DataCarrier with per-peer BatchQueue.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/profiling/ebpf/analyze/EBPFProfilingAnalyzer.java	Name EBPF fetch thread pool threads.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/hierarchy/HierarchyService.java	Name hierarchy auto-matching scheduler thread.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/exporter/ExporterService.java	Simplify exporter service interface (remove start()).
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/config/group/EndpointNameGrouping.java	Name endpoint URI recognition scheduler thread.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/cache/CacheUpdateTimer.java	Name cache update scheduler thread.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/TopNWorker.java	Switch TopN persistence to shared BatchQueue + per-type handler.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/TopNStreamProcessor.java	Pass TopN class into worker to register handler.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsStreamProcessor.java	Unify OAL/MAL aggregation & persistence workers onto shared queues.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsPersistentMinWorker.java	Replace L2 persistence DataCarrier with unified BatchQueue + queue metrics.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsPersistentMinOALWorker.java	Remove OAL-specific L2 worker (unified queue).
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsPersistentMinMALWorker.java	Remove MAL-specific L2 worker (unified queue).
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsAggregateWorker.java	Replace L1 DataCarrier pools with unified BatchQueue + queue metrics.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsAggregateOALWorker.java	Remove OAL-specific L1 worker (unified queue).
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsAggregateMALWorker.java	Remove MAL-specific L1 worker (unified queue).
oap-server/server-core/pom.xml	Replace datacarrier dependency with library-batch-queue.
oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmCore.java	Name the alarm scheduler thread.
oap-server/microbench/src/main/java/org/apache/skywalking/oap/server/microbench/library/datacarrier/common/AtomicRangeIntegerV2.java	Remove microbench datacarrier artifacts (module removal).
oap-server/microbench/src/main/java/org/apache/skywalking/oap/server/microbench/library/datacarrier/common/AtomicRangeIntegerV1.java	Remove microbench datacarrier artifacts (module removal).
oap-server/microbench/src/main/java/org/apache/skywalking/oap/server/microbench/library/datacarrier/common/AtomicRangeIntegerBenchmark.java	Remove microbench datacarrier artifacts (module removal).
oap-server/microbench/pom.xml	Drop datacarrier dependency from microbench module.
oap-server/exporter/src/test/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporterTest.java	Adjust tests for new exporter queue lifecycle and method names.
oap-server/exporter/src/test/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporterProviderTest.java	Update config assertions for new buffer setting field.
oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/kafka/trace/KafkaTraceExporter.java	Replace exporter DataCarrier with BatchQueue.
oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/kafka/log/KafkaLogExporter.java	Replace exporter DataCarrier with BatchQueue.
oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCMetricsExporter.java	Replace exporter DataCarrier with BatchQueue.
oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/ExporterSetting.java	Simplify exporter buffer config to a single bufferSize.
oap-server/exporter/pom.xml	Replace datacarrier dependency with library-batch-queue.
docs/en/setup/backend/grafana-instance.json	Update Grafana instance dashboard panels/labels for unified queues and slot.
docs/en/setup/backend/grafana-cluster.json	Update Grafana cluster dashboard panels/labels for unified queues and slot.
docs/en/changes/changes.md	Document new module, migration details, and thread naming inventory.

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