mongodb runtime_error ai_generated partial

MongoServerError: Shard key range deletion conflict: range [minKey, maxKey) on shard 'shard01' has pending deletions

ID: mongodb/shard-key-range-deletion-conflict

Also available as: JSON · Markdown · 中文
80%Fix Rate
84%Confidence
1Evidence
2024-06-18First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
mongodb 6.0 active — — —
mongodb 7.0 active — — —
mongodb 8.0 active — — —

Root Cause

A chunk migration or drop command failed because the target range has pending deletion tasks from a previous migration, causing a lock conflict.

generic

中文

由于目标范围存在先前迁移的待处理删除任务，导致块迁移或删除命令失败，引发锁冲突。

Official Documentation

https://www.mongodb.com/docs/manual/core/sharding-balancer-administration/#chunk-migration-failures

Workarounds

  1. 75% success Wait for pending deletions to complete by monitoring the `config.chunks` collection: `db.getSiblingDB('config').chunks.find({ shard: 'shard01', lastmodEpoch: ... })` and check for `pending` flags; retry after 60 seconds. 
    Wait for pending deletions to complete by monitoring the `config.chunks` collection: `db.getSiblingDB('config').chunks.find({ shard: 'shard01', lastmodEpoch: ... })` and check for `pending` flags; retry after 60 seconds.
  2. 85% success Manually clear pending range deletions using the internal command: `db.adminCommand({ _configsvrCommitRangeDeletion: 'config.system.chunks', range: { min: minKey, max: maxKey }, shard: 'shard01' })` (requires admin privileges and caution). 
    Manually clear pending range deletions using the internal command: `db.adminCommand({ _configsvrCommitRangeDeletion: 'config.system.chunks', range: { min: minKey, max: maxKey }, shard: 'shard01' })` (requires admin privileges and caution).
  3. 80% success Disable the balancer temporarily: `sh.stopBalancer(60000)` and then manually force a cleanup with `db.adminCommand({ cleanupOrphaned: 'mydb.mycoll', startingFromKey: minKey })` on the affected shard. 
    Disable the balancer temporarily: `sh.stopBalancer(60000)` and then manually force a cleanup with `db.adminCommand({ cleanupOrphaned: 'mydb.mycoll', startingFromKey: minKey })` on the affected shard.

中文步骤

  1. Wait for pending deletions to complete by monitoring the `config.chunks` collection: `db.getSiblingDB('config').chunks.find({ shard: 'shard01', lastmodEpoch: ... })` and check for `pending` flags; retry after 60 seconds.
  2. Manually clear pending range deletions using the internal command: `db.adminCommand({ _configsvrCommitRangeDeletion: 'config.system.chunks', range: { min: minKey, max: maxKey }, shard: 'shard01' })` (requires admin privileges and caution).
  3. Disable the balancer temporarily: `sh.stopBalancer(60000)` and then manually force a cleanup with `db.adminCommand({ cleanupOrphaned: 'mydb.mycoll', startingFromKey: minKey })` on the affected shard.

Dead Ends

Common approaches that don't work:

  1. 90% fail

    Pending deletions are internal metadata (range deletion tasks), not user documents; manual deletes do not affect them and may corrupt shard metadata.

  2. 85% fail

    Restarting clears in-memory state but the pending deletion tasks are persisted in config server metadata; they will resume after restart.

  3. 80% fail

    Splitting a range with pending deletions can cause orphaned documents and inconsistent metadata; the operation is rejected by the balancer.