Upgrade urgency LOW: This is the second release candidate of Valkey 8.0, which generally includes stability and performance improvements over the first release candidate. This release is fully compatible with Redis OSS 7.2.4.

New Features

• Add support for setting the group on a unix domain socket. (#901)
• Experimental - RDMA: Support user keepalive command. (#916)

Logging and Tooling Improvements

• Improve logging when a cluster is unable to failover. (#780)
• Add epoch information to failover auth denied logs. (#816)
• Improve messaging when valkey-cli cluster --fix meet check failed. (#867)
• Log unexpected $ENDOFF responses in dual channel replication. (#839)
• Skip IPv6 tests when it is unsupported on TCLSH. (#910)
• Add a light weight version of DEBUG OBJECT. (#881)
• Add lfu support for DEBUG OBJECT command, added lfu_freq and lfu_access_time_minutes fields. (#479)

Bug fixes

• Correctly expose client infomation in the slowlog when running commands in scripts. (#805)
• Fix a bug where lastbgsave_status was unecessarily being updated when dual channel replication failed. (#811)
• Fix a bug which caused dual channel replication to get stuck because of a TLS issue. (#837)
• Fix a bug which caused bouncing -REDIRECT messages during a FAILOVER (#871)
• Avoid re-establishing replication to a node that is already the primary in CLUSTER REPLICATE. (#884)
• Fix CLUSTER SETSLOT with BLOCK to only wait for replicas that are online. (#879)
• Fix valkey-cli to make source node ignores NOREPLICAS when doing the last CLUSTER SETSLOT (#928)
• Exclude '.' and ':' from isValidAuxChar's banned charset to better support IPV6 addresses. (#963)
• Better handle -REDIRECT messages in the MULTI context. (#895)

Performance

• Improve multithreaded performance with memory prefetching. (#861)
• Optimize ZUNION[STORE] command by removing unnecessary accumulator dict. (#829)
• Optimize linear search of WAIT and WAITAOF when unblocking the client. (#787)
• Move prepareClientToWrite out of loop for lrange command to remove redundant calls. (#860)
• Optimize various commands by using sdsAllocSize instead of sdsZmallocSize. (#923)
• Using intrinsics to optimize counting HyperLogLog trailing bits. (#846)
• Free client's MULTI state when it becomes dirty to reduce memory usage. (#961)
• Optimize the fast path of SET if the expiration time has already expired. (#865)

Compatibility Improvements

• Add 4 sentinel command GET-PRIMARY-ADDR-BY-NAME, PRIMARY, PRIMARIES, and IS-PRIMARY-DOWN-BY-ADDR to allow clients to use inclusive language. (#789)

Behavior Changes

• Block unsubscribe related commands for clients that are not in subscribed mode. (#759)

Configuration Changes

• Change repl-backlog-size from 1MB to 10MB by default. (#911)
• Remove the protected flag from dual-channel-replication. (#908)
• Add configuration hide-user-data-from-log to hide user data from server logs. (#877)
• Change all the lazyfree configurations to yes by default. (#913)