用大神监控redis——监控条件

Question

我试图用 god 监控 redis，但 god 试图重新启动它，即使它已经在运行。这是我的 .god 脚本(移植自 http://blog.thomasmango.com/post/636319317/resque-in-production ):

# Redis
%w{6379}.each do |port|
  God.watch do |w|
    w.name = "redis-server"
    w.interval = 30.seconds
    w.start = "/etc/init.d/redis-server start"
    w.stop = "/etc/init.d/redis-server stop"
    w.restart = "/etc/init.d/redis-server restart"
    w.start_grace = 10.seconds
    w.restart_grace = 10.seconds

    w.start_if do |start|
      start.condition(:process_running) do |c|
          c.interval = 5.seconds
          c.running = false
      end
    end
  end
end

现在当我像这样开始上帝时:

god -c /home/phlegx/workspace/projectx/config/god/config.god -D --log-level debug

我得到以下输出:

I [2011-04-28 18:32:10]  INFO: Loading /home/phlegx/workspace/projectx/config/god/config.god
I [2011-04-28 18:32:10]  INFO: Syslog enabled.
I [2011-04-28 18:32:10]  INFO: Using pid file directory: /var/run/god
I [2011-04-28 18:32:10]  INFO: Started on drbunix:///tmp/god.17165.sock
I [2011-04-28 18:32:10]  INFO: redis-server move 'unmonitored' to 'up'
D [2011-04-28 18:32:10] DEBUG: driver schedule #<God::Conditions::ProcessRunning:0x000000020929d0> in 0 seconds
I [2011-04-28 18:32:10]  INFO: redis-server moved 'unmonitored' to 'up'
I [2011-04-28 18:32:10]  INFO: redis-server [trigger] process is not running (ProcessRunning)
D [2011-04-28 18:32:10] DEBUG: redis-server ProcessRunning [true] {true=>:start}
I [2011-04-28 18:32:10]  INFO: redis-server move 'up' to 'start'
I [2011-04-28 18:32:10]  INFO: redis-server start: /etc/init.d/redis-server start
D [2011-04-28 18:32:20] DEBUG: driver schedule #<God::Conditions::ProcessRunning:0x000000020929d0> in 0 seconds
I [2011-04-28 18:32:20]  INFO: redis-server moved 'up' to 'up'
I [2011-04-28 18:32:20]  INFO: redis-server [trigger] process is not running (ProcessRunning)
D [2011-04-28 18:32:20] DEBUG: redis-server ProcessRunning [true] {true=>:start}
I [2011-04-28 18:32:20]  INFO: redis-server move 'up' to 'start'
I [2011-04-28 18:32:20]  INFO: redis-server start: /etc/init.d/redis-server start

D [2011-04-28 18:32:30] DEBUG: driver schedule #<God::Conditions::ProcessRunning:0x000000020929d0> in 0 seconds
I [2011-04-28 18:32:30]  INFO: redis-server moved 'up' to 'up'
I [2011-04-28 18:32:30]  INF (ProcessRunning)O: redis-server [trigger] process is not running
D [2011-04-28 18:32:30] DEBUG: redis-server ProcessRunning [true] {true=>:start}
I [2011-04-28 18:32:30]  INFO: redis-server move 'up' to 'start'
I [2011-04-28 18:32:30]  INFO: redis-server start: /etc/init.d/redis-server start

如您所见，它总是提示:

INF (ProcessRunning)O: redis-server [trigger] process is not running

有谁知道这可能导致什么？

god 写到“/var/run/god/redis-server.pid”的 PID 似乎和我执行“ps”时不一样:

ps aux | grep redis
redis     7702  0.0  0.0   9876  1376 ?        Ss   18:00   0:01 /usr/bin/redis-server /etc/redis/redis.conf

“redis-server.pid”中的PID不应该和“ps”显示的一样吗？

Answer 1

我不熟悉 god (ehehe)，但我怀疑它希望 Redis 不会自行守护进程(就像 daemontools 那样)。如果是这种情况，您应该关闭 redis 配置文件中的 self 守护进程。 IIRC 是“daemonize=yes”参数，改成no。这可能对你有用。

现在，如果是这种情况，PID 文件可能不同的原因是 god 可能正在启动它并记录 PID，然后当 redis-server 命令返回时它认为 Redis 已死并尝试重新启动。此时它将记录一个新的 PID。如果正在运行的 PID 小于文件中的 PID，这很明显。