Report discarded log bytes

[adinauer]

📜 Description

Report discarded log size in bytes as part of client reports.

💡 Motivation and Context

Since log count is not shown to customers in UI, we want to report log size too.

💚 How did you test it?

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	315.89 ms	362.42 ms	46.53 ms
Size	1.58 MiB	2.12 MiB	553.97 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
806307f	357.85 ms	424.64 ms	66.79 ms
ee747ae	554.98 ms	611.50 ms	56.52 ms
17a0955	372.53 ms	446.70 ms	74.17 ms
2124a46	319.19 ms	415.04 ms	95.85 ms
9fbb112	404.51 ms	475.65 ms	71.14 ms
b6702b0	395.86 ms	409.98 ms	14.12 ms
ee747ae	357.79 ms	421.84 ms	64.05 ms
27d7cf8	314.17 ms	347.00 ms	32.83 ms
9fbb112	361.43 ms	427.57 ms	66.14 ms
96449e8	361.30 ms	423.39 ms	62.09 ms

App size

Revision	Plain	With Sentry	Diff
806307f	1.58 MiB	2.10 MiB	533.42 KiB
ee747ae	1.58 MiB	2.10 MiB	530.95 KiB
17a0955	1.58 MiB	2.10 MiB	533.20 KiB
2124a46	1.58 MiB	2.12 MiB	551.51 KiB
9fbb112	1.58 MiB	2.11 MiB	539.18 KiB
b6702b0	1.58 MiB	2.12 MiB	551.79 KiB
ee747ae	1.58 MiB	2.10 MiB	530.95 KiB
27d7cf8	1.58 MiB	2.12 MiB	549.42 KiB
9fbb112	1.58 MiB	2.11 MiB	539.18 KiB
96449e8	1.58 MiB	2.11 MiB	539.35 KiB

Previous results on branch: feat/report-discarded-log-bytes

Startup times

Revision	Plain	With Sentry	Diff
fff4795	309.94 ms	370.50 ms	60.56 ms
28b566b	316.37 ms	364.56 ms	48.19 ms
38a53b3	368.63 ms	443.27 ms	74.63 ms
c63bfc6	368.17 ms	374.78 ms	6.60 ms

App size

Revision	Plain	With Sentry	Diff
fff4795	1.58 MiB	2.12 MiB	551.81 KiB
28b566b	1.58 MiB	2.12 MiB	551.58 KiB
38a53b3	1.58 MiB	2.12 MiB	552.02 KiB
c63bfc6	1.58 MiB	2.12 MiB	553.32 KiB

[stefanosiano]

Looks good for the most part, but reading the doc i understood we shouldn't count json characters in the byte size, which we are doing here
Perhaps a simple method in the log object that counts each key and value bytes is a good alternative?

[adinauer]

We're currently discussing, whether this simplified count as if it were serialized is OK or if we want to replicate what relay is doing.

[alexander-alderman-webb]

Looks good!

To record: no scientific byte count needed, as users are not billed on logs that are dropped in the SDK. So while the logic differs slightly from relay, counting the bytes in the serialized JSON emitted by the SDK seems like the most pragmatic choice and good enough for this use case.

[cursor]

Bug: Untracked Log Bytes Skew Reports

When processLogEvent drops a log event via event processors, it only records DataCategory.LogItem but not DataCategory.LogByte. This is inconsistent with beforeSendLog handling (lines 1189-1200) where both categories are recorded. Event processors can drop logs at lines 1172-1175 and 1179-1182, causing discarded log bytes to not be tracked in client reports for these code paths.

sentry/src/main/java/io/sentry/SentryClient.java#L472-L502

sentry-java/sentry/src/main/java/io/sentry/SentryClient.java

Lines 472 to 502 in 4a585ad

	@Nullable
	private SentryLogEvent processLogEvent(
	@NotNull SentryLogEvent event, final @NotNull List<EventProcessor> eventProcessors) {
	for (final EventProcessor processor : eventProcessors) {
	try {
	event = processor.process(event);
	} catch (Throwable e) {
	options
	.getLogger()
	.log(
	SentryLevel.ERROR,
	e,
	"An exception occurred while processing log event by processor: %s",
	processor.getClass().getName());
	}
	if (event == null) {
	options
	.getLogger()
	.log(
	SentryLevel.DEBUG,
	"Log event was dropped by a processor: %s",
	processor.getClass().getName());
	options
	.getClientReportRecorder()
	.recordLostEvent(DiscardReason.EVENT_PROCESSOR, DataCategory.LogItem);
	break;
	}
	}
	return event;
	}

 

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