2.6 Changelog

2.6.3 – Changes

  • SERVER-14302 Fixed: “Equality queries on _id with projection may return no results on sharded collections”
  • SERVER-14304 Fixed: “Equality queries on _id with projection on _id may return orphan documents on sharded collections”

2.6.2 – Changes



  • SERVER-13731 Fixed: “Stack overflow when parsing deeply nested $not query”
  • SERVER-13890 Fixed: “Index bounds builder constructs invalid bounds for multiple negations joined by an $or
  • SERVER-13752 Verified assertion on empty $in clause and sort on second field in a compound index.
  • SERVER-13337 Re-enabled idhack for queries with projection.
  • SERVER-13715 Fixed: “Aggregation pipeline execution can fail with $or and blocking sorts”
  • SERVER-13714 Fixed: “non-top-level indexable $not triggers query planning bug”
  • SERVER-13769 Fixed: “distinct command on indexed field with geo predicate fails to execute”
  • SERVER-13675 Fixed “Plans with differing performance can tie during plan ranking”
  • SERVER-13899 Fixed: “‘Whole index scan’ query solutions can use incompatible indexes, return incorrect results”
  • SERVER-13852 Fixed “IndexBounds::endKeyInclusive not initialized by constructor”
  • SERVER-14073 planSummary no longer truncated at 255 characters
  • SERVER-14174 Fixed: “If ntoreturn is a limit (rather than batch size) extra data gets buffered during plan ranking”
  • SERVER-13789 Some nested queries no longer trigger an assertion error
  • SERVER-14064 Added planSummary information for count command log message.
  • SERVER-13960 Queries containing $or no longer miss results if multiple clauses use the same index.
  • SERVER-14180 Fixed: “Crash with ‘and’ clause, $elemMatch, and nested $mod or regex”
  • SERVER-14176 Natural order sort specification no longer ignored if query is specified.
  • SERVER-13754 Bounds no longer combined for $or queries that can use merge sort.


SERVER-13687 Results of $near query on compound multi-key 2dsphere index are now sorted by distance.

Write Operations

SERVER-13802 Insert field validation no longer stops at first Timestamp() field.


  • SERVER-13993 Fixed: “log a message when shouldChangeSyncTarget() believes a node should change sync targets”
  • SERVER-13976 Fixed: “Cloner needs to detect failure to create collection”


  • SERVER-13616 Resolved: “‘type 7’ (OID) error when acquiring distributed lock for first time”
  • SERVER-13812 Now catches exception thrown by getShardsForQuery for geo query.
  • SERVER-14138 mongos will now correctly target multiple shards for nested field shard key predicates.
  • SERVER-11332 Fixed: “Authentication requests delayed if first config server is unresponsive”



  • SERVER-13750 convertToCapped on empty collection no longer aborts after invariant() failure.
  • SERVER-14056 Moving large collection across databases with renameCollection no longer triggers fatal assertion.
  • SERVER-14082 Fixed: “Excessive freelist scanning for MaxBucket”
  • SERVER-13737 CollectionOptions parser now skips non-numeric for “size”/”max” elements if values non-numeric.

Build and Packaging

  • SERVER-13950 MongoDB Enterprise now includes required dependency list.
  • SERVER-13862 Support for mongodb-org-server installation 2.6.1-1 on RHEL5 via RPM.
  • SERVER-13724 Added SCons flag to override treating all warnings as errors.


  • SERVER-13587 Resolved: “ndeleted in system.profile documents reports 1 too few documents removed”
  • SERVER-13368 Improved exposure of timing information in currentOp.


SERVER-13954 security.javascriptEnabled option is now available in the YAML configuration file.



  • SERVER-13865 Shell now returns correct WriteResult for compatibility-mode upsert with non-OID equality predicate on _id field.
  • SERVER-13037 Fixed typo in error message for “compatibility mode”.

Internal Code

  • SERVER-13794 Fixed: “Unused snapshot history consuming significant heap space”
  • SERVER-13446 Removed Solaris builds dependency on ILLUMOS libc.
  • SERVER-14092 MongoDB upgrade 2.4 to 2.6 check no longer returns an error in internal collections.
  • SERVER-14000 Added new lsb file location for Debian 7.1


  • SERVER-13723 Stabilized tags.js after a change in its timeout when it was ported to use write commands.
  • SERVER-13494 Fixed: “setup_multiversion_mongodb.py doesn’t download 2.4.10 because of non-numeric version sorting”
  • SERVER-13603 Fixed: “Test suites with options tests fail when run with --nopreallocj
  • SERVER-13948 Fixed: “awaitReplication() failures related to getting a config version from master causing test failures”
  • SERVER-13839 Fixed sync2.js failure.
  • SERVER-13972 Fixed connections_opened.js failure.
  • SERVER-13712 Reduced peak disk usage of test suites.
  • SERVER-14249 Added tests for querying oplog via mongodump using --dbpath
  • SERVER-10462 Fixed: “Windows file locking related buildbot failures”

2.6.1 – Changes


SERVER-13739 Repair database failure can delete database files

Build and Packaging

  • SERVER-13287 Addition of debug symbols has doubled compile time
  • SERVER-13563 Upgrading from 2.4.x to 2.6.0 via yum clobbers configuration file
  • SERVER-13691 yum and apt “stable” repositories contain release candidate 2.6.1-rc0 packages
  • SERVER-13515 Cannot install MongoDB as a service on Windows


  • SERVER-13066 Negations over multikey fields do not use index
  • SERVER-13495 Concurrent GETMORE and KILLCURSORS operations can cause race condition and server crash
  • SERVER-13503 The $where operator should not be allowed under $elemMatch
  • SERVER-13537 Large skip and and limit values can cause crash in blocking sort stage
  • SERVER-13557 Incorrect negation of $elemMatch value in 2.6
  • SERVER-13562 Queries that use tailable cursors do not stream results if skip() is applied
  • SERVER-13566 Using the OplogReplay flag with extra predicates can yield incorrect results
  • SERVER-13611 Missing sort order for compound index leads to unnecessary in-memory sort
  • SERVER-13618 Optimization for sorted $in queries not applied to reverse sort order
  • SERVER-13661 Increase the maximum allowed depth of query objects
  • SERVER-13664 Query with $elemMatch using a compound multikey index can generate incorrect results
  • SERVER-13677 Query planner should traverse through $all while handling $elemMatch object predicates
  • SERVER-13766 Dropping index or collection while $or query is yielding triggers fatal assertion



  • SERVER-13500 Changing replica set configuration can crash running members
  • SERVER-13589 Background index builds from a 2.6.0 primary fail to complete on 2.4.x secondaries
  • SERVER-13620 Replicated data definition commands will fail on secondaries during background index build
  • SERVER-13496 Creating index with same name but different spec in mixed version replicaset can abort replication


  • SERVER-12638 Initial sharding with hashed shard key can result in duplicate split points
  • SERVER-13518 The _id field is no longer automatically generated by mongos when missing
  • SERVER-13777 Migrated ranges waiting for deletion do not report cursors still open


  • SERVER-9358 Log rotation can overwrite previous log files
  • SERVER-13644 Sensitive credentials in startup options are not redacted and may be exposed
  • SERVER-13441 Inconsistent error handling in user management shell helpers

Write Operations

  • SERVER-13466 Error message in collection creation failure contains incorrect namespace
  • SERVER-13499 Yield policy for batch-inserts should be the same as for batch-updates/deletes
  • SERVER-13516 Array updates on documents with more than 128 BSON elements may crash mongod