Buffer telemetry for 25 ms, Lambda's minimum

README.md

@@ -35,7 +35,7 @@ On next invocation your Lambda logs should start appearing in **Telemetry** -> [
 | RECEIVER_PORT                            | Port of the logs http receiver                          | `4243`                               |
 | MAX_ITEMS                                | Maximum number of events that can be buffered in memory | `10000`                              |
 | MAX_BYTES                                | Maximum size in bytes of events that can be buffered    | `262144`                             |
-| TIMEOUT_MS                               | Maximum time (in milliseconds) that a batch is buffered | `1000`                               |
+| TIMEOUT_MS                               | Maximum time (in milliseconds) that a batch is buffered | `25`                                 |
 | AWS_LAMBDA_RUNTIME_API                   | HTTP base URI to the lambda runtime API                 | _Provided by AWS Lambda environment_ |
 | AWS_LAMBDA_RUNTIME_EXTENSION_API_VERSION | Lambda Extension API version date                       | `2020-01-01`                         |
 | AWS_LAMBDA_RUNTIME_TELEMETRY_API_VERSION | Telemetry API version date                              | `2022-07-01`                         |

src/env.test.ts

@@ -23,7 +23,7 @@ describe('parseEnvironmentVariables', () => {
         RECEIVER_ADDRESS: 'sandbox',
         MAX_ITEMS: 10000,
         MAX_BYTES: 262144,
-        TIMEOUT_MS: 1000,
+        TIMEOUT_MS: 25,
         RECEIVER_PORT: 4243,
         sourceToken: 'source_token',
         ingestionUrl: 'https://s123456.lu-trq-1.betterstackdata.com/',

src/env.ts

@@ -18,7 +18,10 @@ const baseSchema = z.object({
   RECEIVER_ADDRESS: z.string().default('sandbox'), // `sandbox` seems to be the default accepted address
   MAX_ITEMS: envNumber.default('10000'), // Maximum number of events that are buffered in memory.
   MAX_BYTES: envNumber.default('262144'), // Maximum size in bytes that the logs are buffered in memory.
-  TIMEOUT_MS: envNumber.default('1000'), // Maximum time (in milliseconds) that a batch is buffered.
+  // Maximum time (in milliseconds) Lambda buffers telemetry before it hands it to the extension; the extension waits for
+  // this hand-off at the end of every invocation, so Lambda's minimum keeps that wait short. Raise it to get fewer, larger
+  // hand-offs in long invocations that log more than 40 lines per second, at that much more time per invocation.
+  TIMEOUT_MS: envNumber.default('25'),
   RECEIVER_PORT: envNumber.default('4243'), // HTTP server receiving port
   // Better Stack source token; SOURCE_TOKEN is preferred, LOGTAIL_TOKEN is kept as a fallback.
   SOURCE_TOKEN: z.string().optional(),

src/extension.test.ts

@@ -45,7 +45,7 @@ describe('telemetrySubscription', () => {
       AWS_LAMBDA_RUNTIME_TELEMETRY_API_VERSION: '2022-07-01',
       RECEIVER_ADDRESS: 'sandbox',
       RECEIVER_PORT: 4243,
-      TIMEOUT_MS: 1000,
+      TIMEOUT_MS: 25,
       MAX_BYTES: 262144,
       MAX_ITEMS: 10000,
     });
@@ -54,7 +54,7 @@ describe('telemetrySubscription', () => {
       schemaVersion: '2022-07-01',
       destination: { protocol: 'HTTP', URI: 'http://sandbox:4243' },
       types: ['platform', 'function'],
-      buffering: { timeoutMs: 1000, maxBytes: 262144, maxItems: 10000 },
+      buffering: { timeoutMs: 25, maxBytes: 262144, maxItems: 10000 },
     });
   });
 });