After applying SUPEE-10415 Magento 1.9.3.3 404s but works fine if redis is removed from the local.xml

Question

As the subject says, after applying the SUPEE-10415 patch, all seems fine until "redis-cli flushall" then we get the annoying "404 error: Page not found." on everything. After a process of elimination, disabling extensions as magento devdocs suggested, nothing seemed to change until we removed the cache tags from the local.xml file.

Curious if anyone has any "ah hah" idea why everything works fine without redis but 404s when it's enabled.

If it's any significance here is the code that I have that only works when removed from the local.xml after patching.

    <cache>
      <backend>Mage_Cache_Backend_Redis</backend>
      <backend_options>
        <server>127.0.0.1</server>
        <port>6379</port>
        <persistent></persistent>
        <database>0</database>
        <password></password>
        <force_standalone>0</force_standalone>
        <connect_retries>1</connect_retries>
        <read_timeout>10</read_timeout>
        <automatic_cleaning_factor>0</automatic_cleaning_factor>
        <compress_data>1</compress_data>
        <compress_tags>1</compress_tags>      
        <compress_threshold>20480</compress_threshold>
        <compression_lib>gzip</compression_lib>
      </backend_options>
    </cache>

Answer 1

I'd give https://magento.stackexchange.com/a/203746/41117 a read.

I had a similar issue when testing SUPEE-10415 and having Redis enabled, if you revert SUPEE-10415 and enable the Developer logs within System > Configuration > Developer > Log Settings and try redis-cli flushall again you should have a PHP warning that points to the root issue, or Redis points to the issue itself (In my case it was a connection issue).

Once you resolve the PHP warning then Redis will function as usual with SUPEE-10415 applied.

Answer 2

For me, It's just Cm_Cache_Backend_Redis line 235 try to check if class Credis_Cluster exist or not.

elseif (class_exists('Credis_Cluster') && array_key_exists('cluster', $options) && !empty($options['cluster'])) {
        $this->_setupReadWriteCluster($options);
    }

Which class is missing in my library. Updating Credis to latest version resolved it.

Answer 3

In my case I was only able to install SUPEE-10415 after installing SUPEE-10266. I hope it helps.