antirez/redis — Issue #322: SLOWLOG related crash in Redis 2.4.4
Author: antirez
Created: 2012-01-30 10:27:44+00:00
State: open

An user reported the following:

I got a, probably similar, error while Redis was under heavy load:

```
[3149] 29 Jan 17:25:33 # === REDIS BUG REPORT START: Cut & paste starting from here ===
[3149] 29 Jan 17:25:33 # Redis 2.4.4 crashed by signal: 11
[3149] 29 Jan 17:25:33 # Failed assertion: (:0)
[3149] 29 Jan 17:25:33 # --- STACK TRACE
[3149] 29 Jan 17:25:33 # ./redis-server() [0x80851f3]
[3149] 29 Jan 17:25:33 # ./redis-server() [0x808ebbf]
[3149] 29 Jan 17:25:33 # ./redis-server(je_free+0x35a) [0x807f0ea]
[3149] 29 Jan 17:25:33 # ./redis-server(slowlogFreeEntry+0x28) [0x807bd28]
[3149] 29 Jan 17:25:33 # ./redis-server(listDelNode+0x32) [0x80514a2]
[3149] 29 Jan 17:25:33 # ./redis-server(slowlogPushEntryIfNeeded+0x77) [0x807beb7]
[3149] 29 Jan 17:25:33 # ./redis-server(call+0x75) [0x80550c5]
[3149] 29 Jan 17:25:33 # ./redis-server(processCommand+0x253) [0x8056c13]
[3149] 29 Jan 17:25:33 # ./redis-server(processInputBuffer+0x57) [0x805e7d7]
[3149] 29 Jan 17:25:33 # ./redis-server(readQueryFromClient+0x85) [0x805e8d5]
[3149] 29 Jan 17:25:33 # ./redis-server(aeProcessEvents+0x12e) [0x8051dee]
[3149] 29 Jan 17:25:33 # ./redis-server(aeMain+0x37) [0x8052187]
[3149] 29 Jan 17:25:33 # ./redis-server(main+0x110) [0x8057890]
[3149] 29 Jan 17:25:33 # /lib32/libc.so.6(__libc_start_main+0xe7) [0xf75b1e37]
[3149] 29 Jan 17:25:33 # ./redis-server() [0x80511b1]
[3149] 29 Jan 17:25:33 # --- INFO OUTPUT
[3149] 29 Jan 17:25:33 # redis_version:2.4.4
redis_git_sha1:00000000
redis_git_dirty:0
arch_bits:32
multiplexing_api:epoll
process_id:3149
uptime_in_seconds:352769
uptime_in_days:4
lru_clock:664857
used_cpu_sys:23251.42
used_cpu_user:16173.52
used_cpu_sys_children:9795.19
used_cpu_user_children:7721.67
connected_clients:12
connected_slaves:0
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0
used_memory:4064789620
used_memory_human:3.79G
used_memory_rss:4084191232
used_memory_peak:4064771596
used_memory_peak_human:3.79G
mem_fragmentation_ratio:1.00
mem_allocator:jemalloc-2.2.5
loading:0
aof_enabled:0
changes_since_last_save:172547
bgsave_in_progress:1
last_save_time:1327854257
bgrewriteaof_in_progress:0
total_connections_received:240
total_commands_processed:3339961223
expired_keys:0
evicted_keys:0
keyspace_hits:3257524674
keyspace_misses:82035803
pubsub_channels:1
pubsub_patterns:0
latest_fork_usec:54424
vm_enabled:0
role:master
db0:keys=19175,expires=0
db1:keys=5431,expires=0
db3:keys=438,expires=0

[3149] 29 Jan 17:25:33 # --- CLIENT LIST OUTPUT
[3149] 29 Jan 17:25:33 # addr=127.0.0.1:37539 fd=6 idle=349310 flags=N db=0 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=slowlog
addr=127.0.0.1:32846 fd=10 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=exists
addr=127.0.0.1:34065 fd=11 idle=26 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=exec
addr=127.0.0.1:34066 fd=12 idle=37759 flags=N db=1 sub=1 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=subscribe
addr=127.0.0.1:40813 fd=5 idle=183759 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=lrem
addr=127.0.0.1:36696 fd=8 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=sismember
addr=127.0.0.1:36734 fd=15 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=hget
addr=127.0.0.1:39132 fd=13 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=get
addr=127.0.0.1:46486 fd=14 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=hget
addr=127.0.0.1:33530 fd=7 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=rpush
addr=127.0.0.1:41346 fd=16 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=7 oll=0 events=rw cmd=hget
addr=127.0.0.1:54446 fd=9 idle=0 flags=N db=1 sub=0 psub=0 qbuf=0 obl=0 oll=0 events=r cmd=rpush

[3149] 29 Jan 17:25:33 # === REDIS BUG REPORT END. Make sure to include from START to END. ===

Segmentation fault
[30611] 29 Jan 17:26:03 * DB saved on disk
```