We are using mongomirror (1.12.0) to sync data between two MongoDB Atlas clusters, both running version 8.x.x with M50 cluster type. The source cluster contains trillions of records, and we have provisioned an AWS EC2 instance based on MongoDB’s recommendations.
However, we encountered Atlas cluster performance issues, primarily due to storage capacity constraints and oplog warnings. Unfortunately, when the synchronization was nearly complete, mongosync returned an error, and we are now unable to restart the process.
Since the sync process took 2–3 days, we want to avoid a full resync. Can you help us troubleshoot and resolve this issue? Thanks!
{“time”:“2025-03-02T07:42:10.164140Z”,“level”:“fatal”,“serverID”:“b19f4939”,“mongosyncID”:“coordinator”,“stack”:[{“func”:“Wrap”,“line”:“246”,“source”:“/data/mci/abe8b1c2298d2753110b6f3ddda28534/src/github.com/10gen/mongosync/internal/labelederror/labelederror_constructors.go”},{“func”:“(*Mongosync).runChangeEventApplicationPhase”,“line”:“393”,“source”:“/data/mci/abe8b1c2298d2753110b6f3ddda28534/src/github.com/10gen/mongosync/internal/mongosync/mongosync_replicate.go”},{“func”:“(*Mongosync).runPhase”,“line”:“160”,“source”:“/data/mci/abe8b1c2298d2753110b6f3ddda28534/src/github.com/10gen/mongosync/internal/mongosync/mongosync_replicate.go”},{“func”:“(*Mongosync).runFromCurrentPhase”,“line”:“89”,“source”:“/data/mci/abe8b1c2298d2753110b6f3ddda28534/src/github.com/10gen/mongosync/internal/mongosync/mongosync_replicate.go”},{“func”:“(*Mongosync).Replicate”,“line”:“73”,“source”:“/data/mci/abe8b1c2298d2753110b6f3ddda28534/src/github.com/10gen/mongosync/internal/mongosync/mongosync_replicate.go”},{“func”:“(*Mongosync).launchReplicationGoroutines.func1”,“line”:“936”,“source”:“/data/mci/abe8b1c2298d2753110b6f3ddda28534/src/github.com/10gen/mongosync/internal/mongosync/mongosync.go”},{“func”:“goexit”,“line”:“1700”,“source”:“/opt/golang/go1.23/src/runtime/asm_amd64.s”}],“error”:{“msErrorLabels”:[“unclassifiedError”],“clientType”:“source”,“operationDescription”:“Change Stream Reader (DDL) is processing change stream.”,“message”:“change event application failed: Change Stream Reader (DDL) failed: failed to iterate change stream: Change Stream Reader (DDL) could not retrieve the next change event using last resume token 8267C0B9A9000000012B0429296E1404 (timestamp = {T:1740683689 I:1}): (ChangeStreamHistoryLost) Executor error during getMore :: caused by :: Resume of change stream was not possible, as the resume point may no longer be in the oplog.”},“message”:“Got an error during replication.”}
