Revert "CLDSRV-838: Change startTime type to ms since epoch"

This reverts commit 294f26c.

Author: dvasilas

lib/utilities/serverAccessLogger.js

@@ -386,6 +386,15 @@ function calculateElapsedMS(startTime, onCloseEndTime) {
     return Number(onCloseEndTime - startTime) / 1_000_000;
 }
 
+function timestampToDateTime643(unixMS) {
+    if (unixMS === undefined || unixMS === null) {
+        return null;
+    }
+
+    // clickhouse DateTime64(3) expects "seconds.milliseconds" (string type).
+    return (unixMS / 1000).toFixed(3);
+}
+
 function logServerAccess(req, res) {
     if (!req.serverAccessLog || !res.serverAccessLog || !serverAccessLogger) {
         return;
@@ -420,7 +429,7 @@ function logServerAccess(req, res) {
         elapsed_ms: calculateElapsedMS(params.startTime, params.onCloseEndTime) ?? undefined,
 
         // AWS access server logs fields https://docs.aws.amazon.com/AmazonS3/latest/userguide/LogFormat.html
-        startTime: params.startTimeUnixMS ?? undefined, // AWS "Time" field - milliseconds since epoch
+        startTime: timestampToDateTime643(params.startTimeUnixMS) ?? undefined, // AWS "Time" field
         requester: getRequester(authInfo) ?? undefined,
         operation: getOperation(req),
         requestURI: getURI(req) ?? undefined,
@@ -480,4 +489,5 @@ module.exports = {
     getBytesSent,
     calculateTotalTime,
     calculateTurnAroundTime,
+    timestampToDateTime643,
 };

schema/server_access_log.schema.json

@@ -62,8 +62,8 @@
             "minimum": 0
         },
         "startTime": {
-            "description": "Milliseconds since Unix epoch, recorded when the server first routes the request. Represents the AWS server access log 'Time' field.",
-            "type": "number"
+            "description": "Timestamp formatted as: 'seconds.milliseconds', recorded when the server first routes the request. Represents the AWS server access log 'Time' field. String type compatible with Clickhouse DateTime64(3) type.",
+            "type": "string"
         },
         "requester": {
             "description": "AWS server access log 'Requester' field. From AWS 'The canonical user ID of the requester, or a - for unauthenticated requests. If the requester was an IAM user, this field returns the requester's IAM user name along with the AWS account that the IAM user belongs to. This identifier is the same one used for access control purposes.'. We don't use null instead of '-' when the requester is missing.",

tests/unit/utils/serverAccessLogger.js

@@ -11,6 +11,7 @@ const {
     getBytesSent,
     calculateTotalTime,
     calculateTurnAroundTime,
+    timestampToDateTime643,
 } = require('../../../lib/utilities/serverAccessLogger');
 
 describe('serverAccessLogger utility functions', () => {
@@ -679,6 +680,48 @@ describe('serverAccessLogger utility functions', () => {
         });
     });
 
+    describe('timestampToDateTime643', () => {
+        it('should convert milliseconds to seconds with 3 decimal places', () => {
+            const startTimeUnixMS = 1234567890000;
+            const result = timestampToDateTime643(startTimeUnixMS);
+            assert.strictEqual(result, '1234567890.000');
+        });
+
+        it('should handle timestamp with milliseconds', () => {
+            const startTimeUnixMS = 1234567890123;
+            const result = timestampToDateTime643(startTimeUnixMS);
+            assert.strictEqual(result, '1234567890.123');
+        });
+
+        it('should handle 0', () => {
+            const startTimeUnixMS = 0;
+            const result = timestampToDateTime643(startTimeUnixMS);
+            assert.strictEqual(result, '0.000');
+        });
+
+        it('should return null when startTimeUnixMS is null', () => {
+            const result = timestampToDateTime643(null);
+            assert.strictEqual(result, null);
+        });
+
+        it('should return null when startTimeUnixMS is undefined', () => {
+            const result = timestampToDateTime643(undefined);
+            assert.strictEqual(result, null);
+        });
+
+        it('should handle small timestamps', () => {
+            const startTimeUnixMS = 1000;
+            const result = timestampToDateTime643(startTimeUnixMS);
+            assert.strictEqual(result, '1.000');
+        });
+
+        it('should handle timestamps with partial milliseconds', () => {
+            const startTimeUnixMS = 1500;
+            const result = timestampToDateTime643(startTimeUnixMS);
+            assert.strictEqual(result, '1.500');
+        });
+    });
+
     describe('logServerAccess', () => {
         let mockLogger;
         let sandbox;
@@ -831,7 +874,7 @@ describe('serverAccessLogger utility functions', () => {
             assert.strictEqual(loggedData.elapsed_ms, 20.5);
 
             // Verify AWS access server log fields
-            assert.strictEqual(loggedData.startTime, 1234567890000);
+            assert.strictEqual(loggedData.startTime, '1234567890.000');
             assert.strictEqual(loggedData.requester, 'canonical123');
             assert.strictEqual(loggedData.operation, 'REST.GET.OBJECT');
             assert.strictEqual(loggedData.requestURI, 'GET /test-bucket/test-key.txt HTTP/1.1');