[BUG] 100k+ open pipe handles causes KeyDB to stop accepting new connections #453
Description
Describe the bug
KeyDB opens a significant amount of pipes on the system (Ubuntu 20.04 - kernel 5.4.0-113) and is unable to handle any new connections. Existing connections remain stable. Running keydb-cli hangs and keydb-diagnostic-tool reports too many open files.
Open handles:
root@redis1:~# lsof | grep keydb | wc -l
116736
root@redis1:~# keydb-diagnostic-tool
Could not connect to Redis at 127.0.0.1:6379: Can't create socket: Too many open files
Segmentation fault (core dumped)
lsof output snippet:
keydb-ser 16232 keydb 13r FIFO 0,13 0t0 266389 pipe
keydb-ser 16232 keydb 14w FIFO 0,13 0t0 266389 pipe
keydb-ser 16232 keydb 15r FIFO 0,13 0t0 722606 pipe
keydb-ser 16232 keydb 16r FIFO 0,13 0t0 266488 pipe
keydb-ser 16232 keydb 17w FIFO 0,13 0t0 266488 pipe
keydb-ser 16232 keydb 18r FIFO 0,13 0t0 266606 pipe
keydb-ser 16232 keydb 19w FIFO 0,13 0t0 266606 pipe
To reproduce
Unknown, KeyDB ran stable for ~1 month and then experienced this bug.
Expected behavior
KeyDB should maintain a reasonable number of pipes.
Additional information
Running KeyDB 6.3.1 standalone on Ubuntu 20.04 from the keydb.dev repo.
Configuration is mostly default, this installation is using active-active replication between 2 members. Authentication is enabled and there are about 15 TCP connections to the DB. Both replicas exhibit the same issue with 100k open pipe handles.
The DB is still in the above state so happy to run any diagnostic commands necessary.