# Mongrel stops responding after period of inactivity

**URL:** <https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671>\
**Category:** Rails\
**Created:** [July 29, 2007, 11:18am UTC](https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671 "2007-07-29T11:18:55Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Olly\_L](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/eb8c5e/32.png) [@Olly\_L](https://www.ruby-forum.com/u/Olly_L)\
**Post date:** [July 29, 2007, 11:18am UTC](https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671/1 "2007-07-29T11:18:55Z")

</div>

Hi

I’m running a 2-instance Mongrel cluster behind Apache 2.2.4 with  
Rails 1.2.3. If no requests are received by the application for  
several hours (this usually happens overnight) then Mongrel stops  
responding and no requests are detected by Rails (at least nothing is  
in the Rails log). Nothing untoward is in the Mongrel log.

If you try and visit the application, the request times out with a 502  
Proxy Error. Apache is still up and running and serving static files  
without a problem, but the following is present in the Apache error  
log (from trying to hit the SessionController, identified by /  
sessions) which may provide a clue:

```
[Sun Jul 29 08:37:36 2007] [error] proxy: error reading status

```

line from remote server 127.0.0.1  
[Sun Jul 29 08:37:36 2007] [error] proxy: Error reading from  
remote server returned by /sessions

Restarting the Mongrel cluster resolves the problem until the next  
time it happens. I have done a lot of reading about this issue online  
and a number of sources – including the Mongrel FAQ – point to being  
able to fix a ‘hanging mongrel’ situation by setting this value in  
environment.rb:

```
ActiveRecord::Base.verification_timeout = 14400

```

This make the ActiveRecord timeout value less than the MySQL default  
of 28800. I have made this change and it doesn’t appear to make a  
difference.

Can anyone advise me on what to try next to diagnose this issue? I’m  
quickly running out of ideas and I’d appreciate a bit of help!

Here are the vitals from our Ubuntu 6.0.6 server:

```
MySQL
    Ver 14.12 Distrib 5.0.22, for pc-linux-gnu (x86_64) using

```

readline 5.1  
connect\_timeout 5  
interactive\_timeout 28800  
max\_connect\_errors 10  
max\_connections 100  
max\_user\_connections 0  
wait\_timeout 28800

```
ruby 1.8.6 (2007-03-13 patchlevel 0) [x86_64-linux]
    cgi_multipart_eof_fix (2.2)
    fastthread (1.0)
    mongrel (1.0.1)
    mongrel_cluster (1.0.2)

Apache/2.2.4 (Unix)

Mongrel Cluster Config:
    port: "8000"
    environment: production
    address: 127.0.0.1
    pid_file: log/mongrel.pid
    servers: 2
    user: [the user]
    group: [the group]

Apache Load Balancer setup:
    <Proxy balancer://appname_cluster>
    BalancerMember http://127.0.0.1:8000
    BalancerMember http://127.0.0.1:8001
    </Proxy>

Apache Loaded Modules:
    core_module (static)
    authn_file_module (static)
    authn_default_module (static)
    authz_host_module (static)
    authz_groupfile_module (static)
    authz_user_module (static)
    authz_default_module (static)
    auth_basic_module (static)
    cache_module (static)
    include_module (static)
    filter_module (static)
    deflate_module (static)
    log_config_module (static)
    env_module (static)
    headers_module (static)
    setenvif_module (static)
    proxy_module (static)
    proxy_connect_module (static)
    proxy_ftp_module (static)
    proxy_http_module (static)
    proxy_ajp_module (static)
    proxy_balancer_module (static)
    ssl_module (static)
    mpm_prefork_module (static)
    http_module (static)
    mime_module (static)
    status_module (static)
    autoindex_module (static)
    asis_module (static)
    cgi_module (static)
    negotiation_module (static)
    dir_module (static)
    actions_module (static)
    userdir_module (static)
    alias_module (static)
    rewrite_module (static)
    so_module (static)
    php5_module (shared)
    info_module (shared)
```

---

<div class="post-metadata">

**Author:** ![Olly\_L](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/eb8c5e/32.png) [@Olly\_L](https://www.ruby-forum.com/u/Olly_L)\
**Post date:** [July 29, 2007, 11:45am UTC](https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671/2 "2007-07-29T11:45:59Z")

</div>

I had the same problem exactly with a debian server.  
Setting the verification timeout didn’t help, so I had to put a cron job  
to  
wget localhost on both ports every ten minutes.  
The solution may be stupid, but since the admin of the server never gave  
me  
the root account (and the security settings are FBI -like ), I couldn’t  
think of anything else.  
The strange thing is that we are running 3-4 production and development  
boxes that never hang even if mongrel stays inactive for days. (gentoo,  
arch  
mainly).  
My guess is that it has something to do with the debian version of mysql  
or  
some insane security settings.

---

<div class="post-metadata">

**Author:** ![Olly\_L](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/eb8c5e/32.png) [@Olly\_L](https://www.ruby-forum.com/u/Olly_L)\
**Post date:** [July 29, 2007, 1:31pm UTC](https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671/3 "2007-07-29T13:31:17Z")

</div>

Thanks for the reply. I wonder whether upgrading to Ubuntu Edge or  
even Feisty might help, although that seems like quite a drastic  
option.

I’d still like to know why it’s actually happening, so if anyone has  
any other ideas of how to track down the root of the problem I’m all  
ears!

Cheers.

---

<div class="post-metadata">

**Author:** ![Olly\_L](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/eb8c5e/32.png) [@Olly\_L](https://www.ruby-forum.com/u/Olly_L)\
**Post date:** [August 1, 2007, 10:21am UTC](https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671/4 "2007-08-01T10:21:41Z")

</div>

[also posted to the Mongrel Users list]

I thought I’d follow up on my progress with this thread. I haven’t  
seen the problem now for a couple of days so (fingers crossed) my  
problem appears to be fixed.

Firstly, I DO have logrotate scheduled to run daily using cron but I  
didn’t touch this, so I don’t believe this is the problem in my case.

I initially tried setting the following in environment.rb

```
    ActiveRecord::Base.verification_timeout = 14400

```

This did NOT solve my problem, but is probably a change which should  
be made anyway. I then made two significant changes:

1. I didn’t have the MySQL gem installed, so I installed the latest  
version (version 2.7).

2. I made the following change to my Apache Virtual Host setting to  
prevent Apache from losing the connection to the proxy (according to  
[mod\_proxy - Apache HTTP Server](http://httpd.apache.org/docs/2.0/mod/mod_proxy.html))

After making these two changes and restarting MySQL, Apache and the  
Mongrel Cluster, the problem hasn’t reoccurred.

Hope this helps people in the future.

Cheers, Olly

---

<div class="post-metadata">

**Author:** ![Olly\_L](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/eb8c5e/32.png) [@Olly\_L](https://www.ruby-forum.com/u/Olly_L)\
**Post date:** [November 30, 2007, 12:08am UTC](https://www.ruby-forum.com/t/mongrel-stops-responding-after-period-of-inactivity/110671/5 "2007-11-30T00:08:28Z")

</div>

Hi,

This post is kinda old, so I don’t know if you’re still interested…  
It it is the mysql driver which is causing problems. I uninstalled it  
and it working fine now.

Tiberiu