I just recently set up a mixture of RHEL 6.1 Rackspace cloud hosts and RHEL 6.2 dedicated hosts using Rackconnect. I am experiencing intermittent Redis timeouts from within our Rails 3.2.8 app with Redis 2.4.16 running on the RHEL 6.2 dedicated hosts. There is no network latency or packet loss. Also there are no errors on any interfaces on our cloud or dedicated servers or on the managed firewall from Rackspace. When Redis timesout, there is nothing logged within redis even though it is set up to do debug logging. The only error we receive is from Airbrake saying there was a Redis timeout. Network topology: RHEL 6.1 cloud hosts <--> Alert logic IDS <--> Cisco ASA 5510 <--> RHEL 6.2 dedicated hosts (web nodes) (two way NAT) (db hosts running redis) Ping from db host to web host: 64 bytes from 10.181.230.180: icmp_seq=998 ttl=64 time=0.520 ms 64 bytes from 10.181.230.180: icmp_seq=999 ttl=64 time=0.579 ms 64 bytes from 10.181.230.180: icmp_seq=1000 ttl=64 time=0.482 ms --- web1.xxxxxx.com ping statistics --- 1000 packets transmitted, 1000 received, 0% packet loss, time 999007ms rtt min/avg/max/mdev = 0.359/0.535/5.684/0.200 ms Ping from web host to db host: 64 bytes from 192.168.100.26: icmp_seq=998 ttl=64 time=0.544 ms 64 bytes from 192.168.100.26: icmp_seq=999 ttl=64 time=0.452 ms 64 bytes from 192.168.100.26: icmp_seq=1000 ttl=64 time=0.529 ms --- data1.xxxxxx.com ping statistics --- 1000 packets transmitted, 1000 received, 0% packet loss, time 999017ms rtt min/avg/max/mdev = 0.358/0.499/6.120/0.201 ms Redis config: daemonize yes pidfile /var/run/redis/6379/redis_6379.pid port 6379 timeout 0 loglevel debug logfile /var/lib/redis/log syslog-enabled yes syslog-ident redis-6379 syslog-facility local0 databases 16 save 900 1 save 300 10 save 60 10000 rdbcompression yes dbfilename dump-6379.rdb dir /var/lib/redis maxclients 10000 maxmemory-policy volatile-lru maxmemory-samples 3 appendfilename appendonly-6379.aof appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb slowlog-log-slower-than 10000 slowlog-max-len 1024 vm-enabled no vm-swap-file /tmp/redis.swap vm-max-memory 0 vm-page-size 32 vm-pages 134217728 vm-max-threads 4 hash-max-zipmap-entries 512 hash-max-zipmap-value 64 list-max-ziplist-entries 512 list-max-ziplist-value 64 set-max-intset-entries 512 zset-max-ziplist-entries 128 zset-max-ziplist-value 64 activerehashing yes Redis-cli info: redis-cli info redis_version:2.4.16 redis_git_sha1:00000000 redis_git_dirty:0 arch_bits:64 multiplexing_api:epoll gcc_version:4.4.6 process_id:4174 uptime_in_seconds:79346 uptime_in_days:0 lru_clock:1064644 used_cpu_sys:13.08 used_cpu_user:19.81 used_cpu_sys_children:1.56 used_cpu_user_children:7.69 connected_clients:167 connected_slaves:0 client_longest_output_list:0 client_biggest_input_buf:0 blocked_clients:6 used_memory:15060312 used_memory_human:14.36M used_memory_rss:22061056 used_memory_peak:15265928 used_memory_peak_human:14.56M mem_fragmentation_ratio:1.46 mem_allocator:jemalloc-3.0.0 loading:0 aof_enabled:0 changes_since_last_save:166 bgsave_in_progress:0 last_save_time:1352823542 bgrewriteaof_in_progress:0 total_connections_received:286 total_commands_processed:507254 expired_keys:0 evicted_keys:0 keyspace_hits:1509 keyspace_misses:65167 pubsub_channels:0 pubsub_patterns:0 latest_fork_usec:690 vm_enabled:0 role:master db0:keys=6,expires=0 edit 1: add redis-cli info output