Redis Shard Rebalance Uneven
Redis cluster slots are unevenly distributed after rebalancing operation.
Category archive
Redis fixes
Published troubleshooting guides for redis issues.
Redis Client Protocol Desync
Redis client protocol desynchronizes when raw bytes are sent without proper framing.
Redis Maxmemory Policy Inappropriate
Redis eviction policy causes cache misses when workload pattern does not match policy.
Redis Memory Fragmentation Ratio High
Redis memory fragmentation is high when allocator cannot coalesce freed blocks.
Redis Replica Promotion Failed
Redis replica cannot be promoted to master when data epoch is stale.
Redis Cluster Importing State Timeout
Redis cluster remains in importing state when MIGRATE command times out.
Redis Cluster Slot Migration Stuck
Redis cluster slot migration gets stuck when keys are locked or network is slow.
Redis Cluster Meet Gossip Failed
Redis cluster CLUSTER MEET fails when nodes cannot communicate over bus port.
Redis Cluster Node Not Responding
Redis cluster node is marked as failing when heartbeat timeout expires.
Redis Read Only Replica Rejection
Redis read-only replica rejects write commands even when replica-read-only is false.
Redis Multi Part Command Failed
Redis multi-part commands fail when connection is dropped mid-command.
Redis Client Caching Mode Error
Redis client caching mode fails when tracking is not enabled or protocol is RESP2.
Redis Dynamic Key Expiration Skewed
Redis key expiration is skewed when system clock changes or NTP sync fails.
Redis Lazyfree Not Releasing Memory
Redis lazyfree does not release memory asynchronously when lazyfree-lazy flags are disabled.
Redis PSYNC Partial Resync Failed
Redis partial resynchronization fails when replication backlog is too small.
Redis Diskless Replication Failed
Redis diskless replication fails when network timeout is shorter than transfer time.
Redis Replica Stale Data Serving
Redis replica serves stale data when replication is broken or lag is high.
Redis Protected Mode Blocking Remote
Redis protected mode blocks remote connections when bind and requirepass are not set.
Redis Authentication Bypass Vulnerability
Redis authentication can be bypassed in certain versions when specific commands are used.
Redis SSL Handshake Failed
Redis TLS connection fails when certificates are expired or protocols do not match.
Redis Module API Incompatibility
Redis module fails to load when compiled for different Redis version.
Redis Active Defrag Not Running
Redis active defragmentation does not run when activedefrag config is disabled.
Redis IO Threads Not Balancing
Redis IO threads do not balance load when thread count is misconfigured.
Redis VM Swapping Deadlock
Redis becomes unresponsive when memory pages are swapped to disk.
Redis THP Blocking Latency
Redis experiences latency spikes when Transparent Huge Pages is enabled on Linux.
Redis Fork Failed for Snapshot
Redis cannot fork for BGSAVE or BGREWRITEAOF when memory overcommit is disabled.
Redis TCP Backlog Overflow
Redis TCP backlog overflows when connection rate exceeds somaxconn setting.
Redis Maxclients Limit Reached
Redis rejects new connections when maxclients limit is reached.
Redis Graph Query Timeout
RedisGraph query times out when traversing large graph patterns without limits.
Redis TimeSeries Aggregation Wrong
Redis TimeSeries aggregation returns incorrect values when bucket alignment is wrong.
Redis Search Index Not Updating
RedisSearch index is not updated when document indexing fails or schema is wrong.
Redis JSON Type Error
RedisJSON commands fail when path expression is invalid or key does not exist.
Redis Bloom Filter False Positive Rate High
Redis bloom filter has high false positive rate when capacity is underestimated.
Redis HyperLogLog Accuracy Issue
Redis HyperLogLog cardinality estimates are inaccurate when precision is too low.
Redis Geo Index Query Slow
Redis geospatial queries are slow when dataset exceeds memory and causes swapping.
Redis Stream Consumer Group Pending
Redis stream consumer group has pending entries when consumers crash without acknowledging.
Redis Transaction WATCH Lost
Redis WATCH causes transaction abort when watched keys are modified before EXEC.
Redis Lua Script Timeout
Redis Lua script times out when execution exceeds lua-time-limit threshold.
Redis PubSub Messages Not Delivered
Redis PubSub messages are lost when subscribers are disconnected or channels are misnamed.
Redis Client Output Buffer Limit Exceeded
Redis disconnects clients when output buffer exceeds configured limits.
Redis Big Key Causing Memory Issues
Redis big keys cause memory fragmentation and slow operations during deletion.
Redis Slowlog Queries Degrading Performance
Redis slow queries block the event loop and cause latency spikes for other clients.
Redis Key Eviction Not Working
Redis key eviction does not occur when maxmemory-policy is set to noeviction.
Redis Sentinel Not Failing Over
Redis Sentinel does not trigger failover when quorum is not reached or configuration is wrong.
Redis Cluster Slot Not Served
Redis cluster returns CLUSTERDOWN when hash slots are not covered by available nodes.
Redis Replication Broken
Redis replica loses connection to master when network partitions or authentication fails.
Redis AOF Rewrite Failed
Redis AOF background rewrite fails when fork() fails or disk space is insufficient.
Redis Persistence RDB Failed
Redis RDB snapshot fails when disk is full or permissions deny write access.
Redis Out of Memory
Redis returns OOM error when maxmemory limit is reached and eviction policy is not configured.
Redis Connection Refused
Redis connection is refused when server is not running, bind address is wrong, or firewall blocks access.