我刚刚使用Rackconnectbuild立了RHEL 6.1 Rackspace云主机和RHEL 6.2专用主机的混合体。 在RHEL 6.2专用主机上运行Redis 2.4.16的情况下，我在Rails 3.2.8应用程序中遇到了间歇性的Redis超时。 没有networking延迟或数据包丢失。 此外，我们的云或专用服务器上的任何接口或Rackspace的托pipe防火墙上都没有错误。
当Redis超时时，即使设置为执行debugging日志logging，redis中也没有logging。 我们收到的唯一错误是Airbrake说有一个Redis超时。
networking拓扑结构：
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) 从数据库主机到networking主机：
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
从Web主机到分贝主机平：
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
Redisconfiguration：
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信息：
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
编辑1 ：添加redis-cli信息输出
解决。 这是由于我们的思科ASA丢弃部分连接/断开的TCP连接。 使用Rackspace更新configuration解决了这个问题。