Release Notes for mongosync 1.10

Upgrades to Embedded Verifier

• In version 1.10, mongosync enables the embedded verifier for forward and reverse directions of reversible migrations.

• mongosync enables the embedded verifier on sharded clusters by default.

Older Version Support

Starting in version 1.10.0, mongosync supports migrations from pre-6.0 source clusters.

mongosync now supports syncs between the following source and destination MongoDB server versions:

To learn more, see:

• Pre-6.0 Migration Limitations.

• Pre-6.0 Migration Permissions.

• Synchronize Data Between Clusters with Different MongoDB Server Major Versions.

Other Notes

Fixed Issues:

• Fixed a bug introduced in v1.3.0 where descending indexes with key values between -1e-9 and 0 could incorrectly migrate as ascending.

• Fixed a bug introduced in v1.9.0 where the embedded verifier could incorrectly report failure if a TTL index was dropped on the source cluster during a migration.

• Fixed a bug introduced in v1.0.0 that caused unversioned 2dsphere indexes to migrate as v3 2dsphere indexes.

• Fixed a bug introduced in v1.9.0 where the embedded verifier incorrectly report failure for collections with TTLs where expireAfterSeconds: 0.

• Mitigated an issue introduced in v1.0.0 that could result in mongosync timing out during initialization when sampling a source collection and pre-splitting the corresponding destination collection.

New Features:

• Added support for migrations with 4.4 and 5.0 source clusters.

• Added full support for embedded verification of reversible migrations. Previously, verification was only supported in the initial forward-direction of a reversible migration.

• Added support for embedded verification of sharded clusters.

• Added support for migrations from 6.0 and 7.0 sources to 8.0 destinations.

• Added a new --disableVerification option and disableVerification setting to mongosync.

Performance Improvements:

• Improved the partitioning algorithm for large source collections. mongosync now directly samples documents from WiredTiger instead of scanning the whole _id index.

Other:

• mongosync now provides RHEL 9 builds.

• mongosync now disallows setting socketTimeoutMS in connection strings. This is a deprecated parameter.

• mongosync now disallows being restarted during commit when verification is enabled.