[exporterhelper] A collector is eventually OOMKilled when one telemetry data is bigger than a batch max_size and the request sizer is bytes

[at-ishikawa]

Component(s)

exporter/exporterhelper

What happened?

Describe the bug

When an exporter has a sending_queue.sizer=bytes and sending_queue.batch.max_size, and one single telemetry data is bigger than sending_queue.batch.max_size, then it starts to consume memory indefinitely, and eventually the collector is OOMKilled.

Steps to reproduce

Set up a collector's configuration with an exporter that supports exporterhelper and include the following configuration.

    sending_queue:
      sizer: bytes
      batch:
        max_size: 10

Then run a collector and send telemetry data. For example, send a trace data by telemetrygen traces --otlp-insecure --traces 1 to OTLP receiver.

What did you expect to see?

Telemetry data should be dropped and output error logs.

What did you see instead?

I couldn't see anything. But CPU usages and memory usages increase, and the process is eventually OOM Killed.
I saw otelcol-dev process was OOMKilled by dmesg.

> sudo dmesg -T | egrep -i 'killed process|oom.kill'
[Fri Apr 18 12:37:16 2025] qemu-system-x86 invoked oom-killer: gfp_mask=0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), order=0, oom_score_adj=200
[Fri Apr 18 12:37:16 2025]  oom_kill_process+0x118/0x280
[Fri Apr 18 12:37:16 2025] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=user.slice,mems_allowed=0,global_oom,task_memcg=/user.slice/user-2013.slice/user@2013.service/app.slice/tmux-spawn-281eff27-82db-4b5a-8dd7-c264f1daffe7.scope,task=otelcol-dev,pid=1542808,uid=2013
[Fri Apr 18 12:37:16 2025] Out of memory: Killed process 1542808 (otelcol-dev) total-vm:32036360kB, anon-rss:24105632kB, file-rss:516kB, shmem-rss:0kB, UID:2013 pgtables:55032kB oom_score_adj:100
[Fri Apr 18 13:14:50 2025] code invoked oom-killer: gfp_mask=0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), order=0, oom_score_adj=100
[Fri Apr 18 13:14:50 2025]  oom_kill_process+0x118/0x280
[Fri Apr 18 13:14:50 2025] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=user.slice,mems_allowed=0,global_oom,task_memcg=/user.slice/user-2013.slice/user@2013.service/app.slice/tmux-spawn-41f0b67f-58b9-4eab-b419-24031351ed25.scope,task=builder,pid=1663701,uid=2013
[Fri Apr 18 13:14:51 2025] Out of memory: Killed process 1663701 (builder) total-vm:27390444kB, anon-rss:23558260kB, file-rss:1500kB, shmem-rss:0kB, UID:2013 pgtables:49208kB oom_score_adj:100
[Fri Apr 18 13:25:41 2025] wpa_supplicant invoked oom-killer: gfp_mask=0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), order=0, oom_score_adj=0
[Fri Apr 18 13:25:41 2025]  oom_kill_process+0x118/0x280
[Fri Apr 18 13:25:41 2025] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=wpa_supplicant.service,mems_allowed=0,global_oom,task_memcg=/user.slice/user-2013.slice/user@2013.service/app.slice/tmux-spawn-1c691201-4657-4fc1-a2fd-746d93188ea9.scope,task=builder,pid=1693988,uid=2013
[Fri Apr 18 13:25:41 2025] Out of memory: Killed process 1693988 (builder) total-vm:39965976kB, anon-rss:24978248kB, file-rss:532kB, shmem-rss:0kB, UID:2013 pgtables:65084kB oom_score_adj:100

Collector version

v0.124.0

Environment information

Environment

OS: Ubuntu 24.04
Compiler: go1.24.1, ocb: v0.124.0

OpenTelemetry Collector configuration

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317

exporters:
  otlp:
    endpoint: localhost:14317
    tls:
      insecure: true
    sending_queue:
      sizer: bytes
      queue_size: 10000
      batch:
        flush_timeout: 1s
        max_size: 10

service:
  pipelines:
    traces:
      receivers: [otlp]
      exporters: [otlp]
  telemetry:
    logs:
      level: debug

Log output

go run ./otelcol-dev --config otel-collector-config.yaml
2025-04-18T11:52:52.486-0700    info    service@v0.124.0/service.go:199 Setting up own telemetry...
2025-04-18T11:52:52.492-0700    debug   builders/builders.go:24 Stable component.
2025-04-18T11:52:52.496-0700    debug   builders/builders.go:24 Stable component.
2025-04-18T11:52:52.496-0700    debug   otlpreceiver@v0.124.0/otlp.go:58        created signal-agnostic logger
2025-04-18T11:52:52.514-0700    info    service@v0.124.0/service.go:266 Starting otelcol-dev... {"Version": "", "NumCPU": 12}
2025-04-18T11:52:52.514-0700    info    extensions/extensions.go:41     Starting extensions...
2025-04-18T11:52:52.515-0700    info    grpc@v1.71.1/clientconn.go:176  [core] original dial target is: "localhost:14317"       {"grpc_log": true}
2025-04-18T11:52:52.517-0700    info    grpc@v1.71.1/clientconn.go:459  [core] [Channel #1]Channel created      {"grpc_log": true}
2025-04-18T11:52:52.517-0700    info    grpc@v1.71.1/clientconn.go:207  [core] [Channel #1]parsed dial target is: resolver.Target{URL:url.URL{Scheme:"passthrough", Opaque:"", User:(*url.Userinfo)(nil), Host:"", Path:"/localhost:14317", RawPath:"", OmitHost:false, ForceQuery:false, RawQuery:"", Fragment:"", RawFragment:""}}   {"grpc_log": true}
2025-04-18T11:52:52.517-0700    info    grpc@v1.71.1/clientconn.go:208  [core] [Channel #1]Channel authority set to "localhost:14317"   {"grpc_log": true}
2025-04-18T11:52:52.523-0700    info    grpc@v1.71.1/resolver_wrapper.go:210    [core] [Channel #1]Resolver state updated: {
  "Addresses": [
    {
      "Addr": "localhost:14317",
      "ServerName": "",
      "Attributes": null,
      "BalancerAttributes": null,
      "Metadata": null
    }
  ],
  "Endpoints": [
    {
      "Addresses": [
        {
          "Addr": "localhost:14317",
          "ServerName": "",
          "Attributes": null,
          "BalancerAttributes": null,
          "Metadata": null
        }
      ],
      "Attributes": null
    }
  ],
  "ServiceConfig": null,
  "Attributes": null
} (resolver returned new addresses)     {"grpc_log": true}
2025-04-18T11:52:52.525-0700    info    grpc@v1.71.1/balancer_wrapper.go:122    [core] [Channel #1]Channel switches to new LB policy "pick_first"       {"grpc_log": true}
2025-04-18T11:52:52.526-0700    info    gracefulswitch/gracefulswitch.go:194    [pick-first-lb] [pick-first-lb 0xc000139f50] Received new config {
  "shuffleAddressList": false
}, resolver state {
  "Addresses": [
    {
      "Addr": "localhost:14317",
      "ServerName": "",
      "Attributes": null,
      "BalancerAttributes": null,
      "Metadata": null
    }
  ],
  "Endpoints": [
    {
      "Addresses": [
        {
          "Addr": "localhost:14317",
          "ServerName": "",
          "Attributes": null,
          "BalancerAttributes": null,
          "Metadata": null
        }
      ],
      "Attributes": null
    }
  ],
  "ServiceConfig": null,
  "Attributes": null
}       {"grpc_log": true}
2025-04-18T11:52:52.527-0700    info    grpc@v1.71.1/balancer_wrapper.go:195    [core] [Channel #1 SubChannel #2]Subchannel created     {"grpc_log": true}
2025-04-18T11:52:52.528-0700    info    grpc@v1.71.1/clientconn.go:563  [core] [Channel #1]Channel Connectivity change to CONNECTING    {"grpc_log": true}
2025-04-18T11:52:52.529-0700    info    grpc@v1.71.1/clientconn.go:364  [core] [Channel #1]Channel exiting idle mode    {"grpc_log": true}
2025-04-18T11:52:52.530-0700    info    grpc@v1.71.1/server.go:690      [core] [Server #3]Server created        {"grpc_log": true}
2025-04-18T11:52:52.531-0700    info    otlpreceiver@v0.124.0/otlp.go:116       Starting GRPC server    {"endpoint": "0.0.0.0:4317"}
2025-04-18T11:52:52.531-0700    info    service@v0.124.0/service.go:289 Everything is ready. Begin running and processing data.
2025-04-18T11:52:52.532-0700    info    grpc@v1.71.1/clientconn.go:1224 [core] [Channel #1 SubChannel #2]Subchannel Connectivity change to CONNECTING   {"grpc_log": true}
2025-04-18T11:52:52.532-0700    info    grpc@v1.71.1/clientconn.go:1344 [core] [Channel #1 SubChannel #2]Subchannel picks a new address "localhost:14317" to connect    {"grpc_log": true}
2025-04-18T11:52:52.533-0700    info    grpc@v1.71.1/server.go:886      [core] [Server #3 ListenSocket #4]ListenSocket created  {"grpc_log": true}
2025-04-18T11:52:52.533-0700    info    pickfirst/pickfirst.go:184      [pick-first-lb] [pick-first-lb 0xc000139f50] Received SubConn state update: 0xc00027e370, {ConnectivityState:CONNECTING ConnectionError:<nil> connectedAddress:{Addr: ServerName: Attributes:<nil> BalancerAttributes:<nil> Metadata:<nil>}}   {"grpc_log": true}
2025-04-18T11:52:52.548-0700    info    grpc@v1.71.1/clientconn.go:1224 [core] [Channel #1 SubChannel #2]Subchannel Connectivity change to READY        {"grpc_log": true}
2025-04-18T11:52:52.548-0700    info    pickfirst/pickfirst.go:184      [pick-first-lb] [pick-first-lb 0xc000139f50] Received SubConn state update: 0xc00027e370, {ConnectivityState:READY ConnectionError:<nil> connectedAddress:{Addr:localhost:14317 ServerName:localhost:14317 Attributes:<nil> BalancerAttributes:<nil> Metadata:<nil>}}  {"grpc_log": true}
2025-04-18T11:52:52.548-0700    info    grpc@v1.71.1/clientconn.go:563  [core] [Channel #1]Channel Connectivity change to READY {"grpc_log": true}
2025-04-18T11:52:55.995-0700    info    transport/http2_server.go:662   [transport] [server-transport 0xc0000f6000] Closing: read tcp 127.0.0.1:4317->127.0.0.1:46322: read: connection reset by peer  {"grpc_log": true}
2025-04-18T11:52:55.997-0700    info    transport/controlbuf.go:577     [transport] [server-transport 0xc0000f6000] loopyWriter exiting with error: transport closed by client  {"grpc_log": true}

Additional context

No response

[github-actions]

Pinging code owners:

• exporter/exporterhelper: @bogdandrutu @dmitryax

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[iblancasa]

I want to work on this.