php is locking a deleted session file
<p>Our php app, running under apache, is occaisionally trying to lock a deleted session file, this hangs the apache process and eventually we run out of processes.</p>

<p>The evidence :</p>

<pre><code>strace : flock(89, LOCK_EX                   -----stuck in flock for File Descriptor 89
</code></pre>

<p>and then :</p>

<p>lsof, for the same process :</p>

<pre><code>httpd 22161 apache 89u ... /var/lib/php/session/sess_mf7svvirg7rbu9l0m5999pm6h4 (deleted)
</code></pre>

<p>Any ideas as to why this is occurring? And what we could do to prevent it?</p>
