I run my own server and have a few dozen WordPress sites. Recently, many updates (plugin and core) have been silently failing. If I try to do the update from the updates page, I get a message like this one:

The update process is starting. This process may take a while on some hosts, so please be patient.

Enabling Maintenance mode…

Updating Plugin Jetpack by WordPress.com (1/1)

But it never progresses further. If I attempt the update from the plugins page, I get

Downloading update from http://downloads.wordpress.org/plugin/jetpack.2.3.1.zip

Downloading update from http://downloads.wordpress.org/plugin/jetpack.2.3.1.zip

But nothing more. There is nothing in either the PHP nor apache error logs, even if I set WP_DEBUG to true.

To be clear, this is happening for several plugins on all sites on this server, so I presume there's a configuration issue or other problem. But I don't know where to start looking to fix and/or debug the problem. Can anyone advise?

PS - The server is running WHM/CPanel, so it's CENTOS 5.8. Apache 2.2, PHP 5.3 (the problem also occurred in 5.2). The problem began when the managed support made some changes that were designed to stop the server overloading.

  • What changes did managed support make?
    – s_ha_dum
    Commented Aug 21, 2013 at 23:20
  • I have made the following changes to your apache optimizations: StartServers 20 -> 3 MinSpareServers 20 -> 3 MaxSpareServers 20 -> 5 Commented Aug 21, 2013 at 23:26
  • I've made a slight adjustment to your server's MySQL configuration to try to clear out connections in MySQL faster: interactive_timeout - 300 > 200 Commented Aug 21, 2013 at 23:28
  • The following actions were taken to prevent this from happening again: adjusted mysql configurations to conserve memory Commented Aug 21, 2013 at 23:31
  • While I am no MySQL server expert, the either the interactive_timeout and the memory adjustment look suspicious to me. MySQL's logs may not be enabled but you could have those switched on to try to trace the source of the problem or have support ease the timeout and the memory settings back up until you get things working.
    – s_ha_dum
    Commented Aug 21, 2013 at 23:50

1 Answer 1


There is a bug in some versions of PHP itself, unzip hangs. PHP 5.2.17 hangs, PHP 5.3.24 works as expected.

PHP Change Log http://www.php.net/ChangeLog-5.php#5.3.4 says PHP Version 5.3.4 released 09-Dec-2010 - "Fixed crash in zip extract method (possible CWE-170)". (Note: 5.3.24 released 11-April-2013, and is no longer the latest version.)

http://lcblog.lernerconsult.com/2013-php-unzip-bug-makes-wordpress-updates-hang/ has the PHP program I used to demonstrate the bug is PHP not WordPress or plugins.

  • Thanks for the suggestion. I'm using PHP 5.3.27, so I don't think this is the issue. Commented Oct 15, 2013 at 22:48

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