Read on view cache file may fail if an other process is generating it concurrently. This issue may result in incomplete or empty page. However, after refreshing the browser page, this issue may be self-fixed.

The possible cause is:

unserialize()

function returns FALSE under such condition.

Here is the code snippet from kernel/classes/eznodeviewfunction.php

$contents = file_get_contents( $file );
$Result = unserialize( $contents );

The possible solutions might be:

1. Adding shared lock before read, but it does not work over NFS.

2. Adding an endless loop to do sleep/retry

Please advise if there is any workaround to fix this issue.

Many thanks in advance,

Michael

Steps to reproduce

Open a browser and access a complicated page, then try to click the refresh button quickly for several times, an empty or incomplete page shows up randomly.