feat: disableSend boolean config option to work, but not communicate with APM server #2127

trentm · 2021-06-24T23:09:39Z

Env var is ELASTIC_APM_DISABLE_SEND. Default is false. This feature is
useful to use the APM agent for async context tracking, distributed
tracing context propagation, and/or log enrichment with trace.id. When
disableSend=true, attempts are made to limit unnecessary processing
(like calculating metrics, encoding stacktraces, etc.).

This is the same as the "disable_send" option in some of the other APM agents.

Fixes: #2101

Checklist

Implement code
Add tests
Update TypeScript typings
Update documentation
Add CHANGELOG.asciidoc entry
Commit message follows commit guidelines
Updated Agent config comparison sheet (Also added it for Java which had already implemented disable_send.)

apmmachine · 2021-06-24T23:27:56Z

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Build Cause: Pull request #2127 updated
Start Time: 2021-06-29T16:26:46.824+0000
Duration: 20 min 14 sec
Commit: 549392b

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…with APM server Env var is ELASTIC_APM_DISABLE_SEND. Default is false. This feature is useful to use the APM agent for async context tracking, distributed tracing context propagation, and/or log enrichment with trace.id. When disableSend=true, attempts are made to limit unnecessary processing (like calculating metrics, encoding stacktraces, etc.). This is the same as the "disable_send" option in some of the other APM agents.

That should suffice to give debugging hint why data isn't being sent and limit log.trace noise sufficiently.

astorm

Does what it says on the tin and a no-op transport object seems like a great way to accomplish this without being too disruptive. Approving -- I'd be fine landing this as is, but it wasn't clear if the NICE_REGEXPS_FIELDS was intended here or not.

astorm · 2021-06-29T05:13:37Z

lib/config.js

@@ -399,9 +407,21 @@ class Config {
      logger: true,
      transport: true
    }
+    const NICE_REGEXPS_FIELDS = {


I didn't see this change mentioned -- this looks like some code that will serialize our "arrays of regular expressions" values as strings so that instead of seeing

{ ignoreUrlRegExp: [{},{}] }

users will see

{ ignoreUrlRegExp: ['/foo','/bar'] }

when serializing the configuration object as JSON. This isn't a particularly hot path so I don't see any issue with the extra work being done here, and (as the comment mentions) it's way more useful than a {}

Question: Since we do use this method when we're logging the agent's configuration on startup, do we want to mention this behavior change/fix in the CHANGELOG? Or just keep it as a quiet quality of life improvement?

I forgot to add a "REVIEW NOTE" for this. This part and the slight change to the 'agent configured correctly' log.trace are an unrelated change. You got it right, however, that this is a "quality of life improvement". When filtering trace output through ecslog, the before and after are:

before:

[2021-06-24T22:12:17.017Z] TRACE (elastic-apm-node): agent configured correctly: {"pid":99484,"ppid":77218,"arch":"x64","platform":"darwin","node":"v12.22.1","agent":"3.16.0","startTrace":["at Agent.start (/Users/trentm/el/apm-agent-nodejs11/lib/agent.js:190:11)","at Object.<anonymous> (/Users/trentm/el/apm-agent-nodejs11/esfoo.js:3:27)","at Module._compile (internal/modules/cjs/loader.js:999:30)","at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)","at Module.load (internal/modules/cjs/loader.js:863:32)","at Function.Module._load (internal/modules/cjs/loader.js:708:14)","at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12)","at internal/main/run_main_module.js:17:47"],"main":"index.js","dependencies":{"@elastic/ecs-pino-format":"^1.1.2","after-all-results":"^2.0.0","async-cache":"^1.1.0","async-value-promise":"^1.1.1","basic-auth":"^2.0.1","cookie":"^0.4.0","core-util-is":"^1.0.2","elastic-apm-http-client":"^9.8.1","end-of-stream":"^1.4.4","error-callsites":"^2.0.4","error-stack-parser":"^2.0.6","escape-string-regexp":"^4.0.0","fast-safe-stringify":"^2.0.7","http-headers":"^3.0.2","is-native":"^1.0.1","load-source-map":"^2.0.0","lru-cache":"^6.0.0","measured-reporting":"^1.51.1","monitor-event-loop-delay":"^1.0.0","object-filter-sequence":"^1.0.0","object-identity-map":"^1.0.2","original-url":"^1.2.3","pino":"^6.11.2","read-pkg-up":"^7.0.1","relative-microtime":"^2.0.0","require-in-the-middle":"^5.0.3","semver":"^6.3.0","set-cookie-serde":"^1.0.0","shallow-clone-shim":"^2.0.0","sql-summary":"^1.0.1","traceparent":"^1.0.0","traverse":"^0.6.6","unicode-byte-truncate":"^1.0.0"},"conf":{"ignoreUrlStr":[],"ignoreUrlRegExp":[],"ignoreUserAgentStr":[],"ignoreUserAgentRegExp":[],"transactionIgnoreUrlRegExp":[],"sanitizeFieldNamesRegExp":[{},{},{},{},{},{},{},{},{},{},{},{},{},{}],"ignoreMessageQueuesRegExp":[],"abortedErrorThreshold":25,"active":true,"apiRequestSize":786432,"apiRequestTime":10,"asyncHooks":true,"breakdownMetrics":true,"captureBody":"off","captureErrorLogStackTraces":"messages","captureExceptions":false,"captureHeaders":true,"captureSpanStackTraces":false,"centralConfig":true,"cloudProvider":"none","disableInstrumentations":[],"disableSend":true,"environment":"development","errorMessageMaxLength":2048,"errorOnAbortedRequests":false,"filterHttpHeaders":true,"ignoreMessageQueues":[],"instrument":true,"instrumentIncomingHTTPRequests":true,"logLevel":"trace","logUncaughtExceptions":false,"maxQueueSize":1024,"metricsInterval":0,"metricsLimit":1000,"sanitizeFieldNames":["password","passwd","pwd","secret","*key","*token*","*session*","*credit*","*card*","authorization","set-cookie","pw","pass","connect.sid"],"serverTimeout":30,"sourceLinesErrorAppFrames":5,"sourceLinesErrorLibraryFrames":5,"sourceLinesSpanAppFrames":0,"sourceLinesSpanLibraryFrames":0,"spanFramesMinDuration":0.01,"stackTraceLimit":50,"transactionIgnoreUrls":[],"transactionMaxSpans":500,"transactionSampleRate":1,"useElasticTraceparentHeader":true,"usePathAsTransactionName":false,"verifyServerCert":true,"serviceName":"elastic-apm-node","serviceVersion":"3.16.0","serverHost":"localhost:8200","serverPort":8200}}

after:

[2021-06-24T22:27:38.034Z] TRACE (elastic-apm-node): agent configured correctly pid: 99836 ppid: 77218 arch: "x64" platform: "darwin" node: "v12.22.1" agent: "3.16.0" startTrace: [ "at Agent.start (/Users/trentm/el/apm-agent-nodejs11/lib/agent.js:190:11)", "at Object.<anonymous> (/Users/trentm/el/apm-agent-nodejs11/esfoo.js:3:27)", "at Module._compile (internal/modules/cjs/loader.js:999:30)", "at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)", "at Module.load (internal/modules/cjs/loader.js:863:32)", "at Function.Module._load (internal/modules/cjs/loader.js:708:14)", "at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12)", "at internal/main/run_main_module.js:17:47" ] main: "index.js" dependencies: { "@elastic/ecs-pino-format": "^1.1.2", "after-all-results": "^2.0.0", "async-cache": "^1.1.0", "async-value-promise": "^1.1.1", "basic-auth": "^2.0.1", "cookie": "^0.4.0", "core-util-is": "^1.0.2", "elastic-apm-http-client": "^9.8.1", "end-of-stream": "^1.4.4", "error-callsites": "^2.0.4", "error-stack-parser": "^2.0.6", "escape-string-regexp": "^4.0.0", "fast-safe-stringify": "^2.0.7", "http-headers": "^3.0.2", "is-native": "^1.0.1", "load-source-map": "^2.0.0", "lru-cache": "^6.0.0", "measured-reporting": "^1.51.1", "monitor-event-loop-delay": "^1.0.0", "object-filter-sequence": "^1.0.0", "object-identity-map": "^1.0.2", "original-url": "^1.2.3", "pino": "^6.11.2", "read-pkg-up": "^7.0.1", "relative-microtime": "^2.0.0", "require-in-the-middle": "^5.0.3", "semver": "^6.3.0", "set-cookie-serde": "^1.0.0", "shallow-clone-shim": "^2.0.0", "sql-summary": "^1.0.1", "traceparent": "^1.0.0", "traverse": "^0.6.6", "unicode-byte-truncate": "^1.0.0" } conf: { "ignoreUrlStr": [], "ignoreUrlRegExp": [], "ignoreUserAgentStr": [], "ignoreUserAgentRegExp": [], "transactionIgnoreUrlRegExp": [], "sanitizeFieldNamesRegExp": [ "/^password$/i", "/^passwd$/i", "/^pwd$/i", "/^secret$/i", "/^.*key$/i", "/^.*token.*$/i", "/^.*session.*$/i", "/^.*credit.*$/i", "/^.*card.*$/i", "/^authorization$/i", "/^set\\x2dcookie$/i", "/^pw$/i", "/^pass$/i", "/^connect\\.sid$/i" ], "ignoreMessageQueuesRegExp": [], "abortedErrorThreshold": 25, "active": true, "apiRequestSize": 786432, "apiRequestTime": 10, "asyncHooks": true, "breakdownMetrics": true, "captureBody": "off", "captureErrorLogStackTraces": "messages", "captureExceptions": false, "captureHeaders": true, "captureSpanStackTraces": false, "centralConfig": true, "cloudProvider": "none", "disableInstrumentations": [], "disableSend": true, "environment": "development", "errorMessageMaxLength": 2048, "errorOnAbortedRequests": false, "filterHttpHeaders": true, "ignoreMessageQueues": [], "instrument": true, "instrumentIncomingHTTPRequests": true, "logLevel": "trace", "logUncaughtExceptions": false, "maxQueueSize": 1024, "metricsInterval": 0, "metricsLimit": 1000, "sanitizeFieldNames": [ "password", "passwd", "pwd", "secret", "*key", "*token*", "*session*", "*credit*", "*card*", "authorization", "set-cookie", "pw", "pass", "connect.sid" ], "serverTimeout": 30, "sourceLinesErrorAppFrames": 5, "sourceLinesErrorLibraryFrames": 5, "sourceLinesSpanAppFrames": 0, "sourceLinesSpanLibraryFrames": 0, "spanFramesMinDuration": 0.01, "stackTraceLimit": 50, "transactionIgnoreUrls": [], "transactionMaxSpans": 500, "transactionSampleRate": 1, "useElasticTraceparentHeader": true, "usePathAsTransactionName": false, "verifyServerCert": true, "serviceName": "elastic-apm-node", "serviceVersion": "3.16.0", "serverHost": "localhost:8200", "serverPort": 8200 }

do we want to mention this behavior change/fix in the CHANGELOG?

I don't think it is significant enough to merit a changelog entry. I don't feel strongly, however.

astorm · 2021-06-29T05:17:21Z

package.json

@@ -79,7 +79,7 @@
  },
  "homepage": "https://github.com/elastic/apm-agent-nodejs",
  "dependencies": {
-    "@elastic/ecs-pino-format": "^1.1.2",
+    "@elastic/ecs-pino-format": "^1.2.0",


just noting the bumped dependency in cast it wasn't intentional.

It was intentional to get this change to support testing log correlation, as commented here:

apm-agent-nodejs/test/disable-send.test.js

Lines 84 to 87 in 3341137

// `_elasticApm` is an internal/test-only option added in

// @elastic/[email protected] to allow passing in the import agent

// package that isn't `require`able at "elastic-apm-node".

const log = pino(ecsFormat({ _elasticApm: apm }), logStream)

trentm · 2021-06-29T17:06:11Z

Notes on perf when using disableSend=true

When disableSend=true is set, the Node.js agent is attempting to avoid some work. The following shows some perf data around this. I ran "node pathosapp.js", a node.js Express simple app, doing this for each request:

function sim_80_17_3(req, res, next) {
    var prob = rng()
    if (prob < 0.8) {
      barSync()
      res.send('syncspans2')
    } else if (prob < 0.97) {
      res.send('ok')
    } else {
      next(new Error('err: ' + prob))
    }
  }

i.e. simulating 80% just a transaction, 17% a transaction + 2 spans, 3% errors. I loaded that to 500 req/s (via hey -c 50 -q 10 -z 60s http://localhost:3000/) on my macos laptop, with profiling enabled to get a flamegraph.

with `disableSend=false` (the default)

CPU usage of the node process was ~50%. This value is only useful as a relative comparison to other runs.

 Latency distribution:
  10% in 0.0050 secs
  25% in 0.0098 secs
  50% in 0.0189 secs
  75% in 0.0268 secs
  90% in 0.0319 secs
  95% in 0.0353 secs
  99% in 0.0479 secs

flamegraph (the shown trim_prefix stack frame is not significant):

with `disableSend=true`

CPU usage: ~30% (a significant drop)
Latency percentiles: a significant improvement

Latency distribution:
  10% in 0.0038 secs
  25% in 0.0073 secs
  50% in 0.0128 secs
  75% in 0.0183 secs
  90% in 0.0223 secs
  95% in 0.0257 secs
  99% in 0.0385 secs

Flamegraph:

This shows a number of Agent-related stacks are gone (it is hard to see this without the interactive flamegraph and some experience with the agent). If future work were done to reduce more overhead here, a starting point would be this stack frame:

startOrResume /Users/trentm/el/apm-agent-nodejs11/node_modules/traceparent/index.js:121:24
Top of Stack: 4.6% (621 of 13528 samples)
On Stack: 5.3% (720 of 13528 samples)

Conclusion: Agent overhead is significantly reduced when using disableSend, which is a good thing for those using the disableSend use case.

trentm · 2021-06-29T17:08:45Z

The failed "Integration Tests" is a common flake I've seen of late. I'm not stopping this PR for it.

…with APM server (elastic#2127) Env var is ELASTIC_APM_DISABLE_SEND. Default is false. This feature is useful to use the APM agent for async context tracking, distributed tracing context propagation, and/or log enrichment with trace.id. When disableSend=true, attempts are made to limit unnecessary processing (like calculating metrics, encoding stacktraces, etc.). This also includes an improvement to the `agent configured correctly` log.trace that dumps the agent config.

trentm self-assigned this Jun 24, 2021

github-actions bot added the agent-nodejs Make available for APM Agents project planning. label Jun 24, 2021

trentm mentioned this pull request Jun 28, 2021

feat: add internal/testing-only opts._elasticApm to facilitate APM agent tests elastic/ecs-logging-nodejs#84

Merged

trentm added 5 commits June 28, 2021 15:16

testing for disableSend=true

dfcb273

just the one log.trace for skipping transaction

f3e963d

That should suffice to give debugging hint why data isn't being sent and limit log.trace noise sufficiently.

changelog entry, configuration docs entry

c820e7a

typings update

426f3f9

trentm force-pushed the trentm/disable_send branch from eb266f8 to 426f3f9 Compare June 28, 2021 22:17

trentm marked this pull request as ready for review June 28, 2021 22:17

trentm added 2 commits June 28, 2021 15:34

fix import path to test util after rebase

42bdd0e

Merge branch 'master' into trentm/disable_send

3341137

trentm mentioned this pull request Jun 29, 2021

add context_propagation_only config option, spec existing disable_send config option elastic/apm#461

Merged

trentm requested a review from astorm June 29, 2021 00:41

astorm approved these changes Jun 29, 2021

View reviewed changes

Merge branch 'master' into trentm/disable_send

549392b

trentm merged commit 28e77af into master Jun 29, 2021

trentm deleted the trentm/disable_send branch June 29, 2021 17:09

trentm mentioned this pull request Oct 26, 2021

implement contextPropagationOnly config var, tweak disableSend behaviour #2393

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feat: disableSend boolean config option to work, but not communicate with APM server #2127

feat: disableSend boolean config option to work, but not communicate with APM server #2127

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trentm commented Jun 29, 2021

trentm commented Jun 29, 2021

	// `_elasticApm` is an internal/test-only option added in
	// @elastic/[email protected] to allow passing in the import agent
	// package that isn't `require`able at "elastic-apm-node".
	const log = pino(ecsFormat({ _elasticApm: apm }), logStream)

feat: disableSend boolean config option to work, but not communicate with APM server #2127

feat: disableSend boolean config option to work, but not communicate with APM server #2127

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trentm commented Jun 24, 2021 • edited Loading

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trentm commented Jun 29, 2021

Notes on perf when using disableSend=true

with disableSend=false (the default)

with disableSend=true

trentm commented Jun 29, 2021

trentm commented Jun 24, 2021 •

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with `disableSend=false` (the default)

with `disableSend=true`