SDK Truncation Logic

[s1gr1d]

Description

Data should not be truncated in the SDK itself, but in Relay.

Reference: https://github.com/getsentry/projects/issues/837

Exceptions:

• 1000 spans per transaction
• max number of breadcrumbs
• request body truncation

Going through the repository, several places were found where truncation happens:

Normalizing objects

• Truncating by depth and breath, configurable with normalizeMaxBreadth and normalizeDepth

sentry-javascript/packages/core/src/utils/normalize.ts

Line 40 in 9d92e97

export function normalize(input: unknown, depth: number = 100, maxProperties: number = +Infinity): any {

Limiting Values

• Maximum value length, configurable with maxValueLength

sentry-javascript/packages/core/src/utils/prepareEvent.ts

Line 135 in ceb003c

const { environment, release, dist, maxValueLength = 250 } = options;

Context lines

• Trims context lines

sentry-javascript/packages/core/src/utils/string.ts

Line 27 in 9d92e97

export function snipLine(line: string, colno: number): string {

Exceptions

• Truncates key length, extra error data

sentry-javascript/packages/core/src/utils/object.ts

Line 179 in 1b41126

export function extractExceptionKeysForMessage(exception: Record<string, unknown>, maxLength: number = 40): string {

sentry-javascript/packages/core/src/integrations/extraerrordata.ts

Line 112 in 1b41126

extraErrorInfo[key] = isError(value) || typeof value === 'string' ? truncate(`${value}`, maxValueLength) : value;

Limiting Zod Errors

• Zod integration limits amount of issues attached (configurable)

sentry-javascript/packages/core/src/integrations/zoderrors.ts

Line 139 in ceb003c

export function applyZodErrorsToEvent(

Breadcrumbs

• Maximum number of breadcrumbs is 100 (this should probably stay)

sentry-javascript/packages/core/src/scope.ts

Line 483 in 1b41126

this._breadcrumbs = this._breadcrumbs.slice(-maxCrumbs);

Feature Flags

• Maximum flags per span
• Maximum flags stored in the buffer
  

  sentry-javascript/packages/core/src/utils/featureFlags.ts

  Line 150 in 1b41126

  if (numOfAddedFlags < maxFlagsPerSpan) {

HTTP integration

• Truncates body, configurable with maxIncomingRequestBodySize
  

  sentry-javascript/packages/node-core/src/integrations/http/SentryHttpInstrumentation.ts

  Lines 553 to 558 in 99360ba

  	const truncatedBody =
  	bodyByteLength > maxBodySize
  	? `${Buffer.from(body)
  	.subarray(0, maxBodySize - 3)
  	.toString('utf-8')}...`
  	: body;

Redis integration

• Truncates span description (not configurable)

sentry-javascript/packages/node/src/integrations/tracing/redis.ts

Line 75 in 5310112

span.updateName(truncate(spanDescription, 1024));

Paths

• Trims path length for directories, LCP URLs

sentry-javascript/packages/core/src/utils/path.ts

Line 59 in ceb003c

const truncated = filename.length > 1024 ? `<truncated>${filename.slice(-1024)}` : filename;

sentry-javascript/packages/browser-utils/src/metrics/lcp.ts

Line 81 in 3c63bec

entry.url && (attributes['lcp.url'] = entry.url.trim().slice(0, 200));

sentry-javascript/packages/browser/src/integrations/globalhandlers.ts

Line 217 in f25a327

return url.slice(0, 1024);

[linear]

JS-857 SDK Truncation Logic