Litespeed users on cPanel WHM servers are realizing the benefits of running Varnish Cache in front of Litespeed to improve performance. While we (UNIXy) don’t officially provide support to subscribers running the cPanel Varnish Plugin with Litespeed, it does work with only a few extra manual steps. Keep in mind that we support this configuration for our fully managed VPS, dedicated server, and cluster clients. If you are a current client and need this configured, please open a ticket request.

In this post, I’m going to list the steps required to pair the cPanel Varnish Plugin with Litespeed on cPanel WHM servers. These few procedures apply to a blank cPanel installation (no Litespeed, no Varnish Plugin). The order below is important so don’t skip!

• 1. Configure your Apache / PHP with the desired options and extentions. Let EasyApache finish the build.
• 2. Install Litespeed using the command line installer with the port offset at 2000 (default).
• 3. From WHM -> Litespeed -> Build Matching PHP binaries. Let the Litespeed builder complete before proceeding.
• 4. Proceed with installing the cPanel Varnish Plugin. Let it complete.
• 5. Set the Litespeed Port offset to zero in Admin Console.
• 6. In Admin Console, Configuration -> Server -> General Settings -> Use Client IP in header -> Yes. Restart Litespeed.

About UNIXY

UNIXY is a long-time Varnish Cache user and evangelist. They have been offering Varnish acceleration to their clients for more than three years. They have released the first cPanel Varnish plugin as well as spun a new startup, Fastlayer, the on-demand HTTP accelerator for the cloud.

That’s all folks! I hope you find this useful.

A default installation of FastCGI on cPanel server is dangerously simple. It’s dangerous because one cPanel account (or one vhost) is capable of crashing down a whole server if, say, traffic were to spike up. It’s also simple because it won’t allow complex scripts to run cleanly. In brief, it’s absolutely not ready for production as-is. In this post, I’ll go over what it takes to configure FastCGI on a cPanel node properly.

Did you know?

UNIXy is a fully managed server and cluster provider. What this means is we don’t expect you to know anything about servers or server management. The good news is it doesn’t cost you extra to have us manage your UNIXy server! Get in touch with us here to get the ball rolling!

Before you continue reading, be sure to have FastCGI up and running as the PHP handler on your cPanel server. The installation of FastCGI is covered in the online cPanel documentation. From here on now, I’ll assume you’re ready to add the settings for FastCGI.

The following is a list of settings that you need to add to /etc/httpd/conf/php.conf upon switching to FastCGI:

MaxRequestsPerProcess 1000
FcgidMaxProcesses 200
FcgidProcessLifeTime 7200
MaxProcessCount 500
FcgidIOTimeout 400
FcgidIdleTimeout 600
FcgidIdleScanInterval 90
FcgidBusyTimeout 300
FcgidBusyScanInterval 80
ErrorScanInterval 3
ZombieScanInterval 3
DefaultMinClassProcessCount 0
DefaultMaxClassProcessCount 3
MaxRequestLen 20468982

You’re more likely to adjust the settings in bold above. DefaultMinClassProcessCount 0 instructs FastCGI to keep zero PHP processes running for user when traffic is idle (cPanel account user) . On the other hand, DefaultMaxClassProcessCount 3 tells FastCGI to never allow more than 3 PHP processes running at a time. This settings prevents one users from crashing the server were they to receive a lot of traffic.

So go ahead and copy/paste the above into your httpd.conf and restart Apache (service httpd restart). You’re good to go now! For greater performance, be sure to check out our Varnish plugin. Whether you’re running suPHP, FastCGI, or even DSO (mod_php), Varnish will make your website load much faster.

That’s all folks!

We haven’t seen anyone explain the meaning of following Varnish error message found in the logs of your server in detail. So here it is for the curious:

Dec  5 12:31:31 server varnishd[28446]: Child (28447) not responding to CLI, killing it.
Dec  5 12:31:59 server varnishd[28446]: Child (28447) died signal=3
Dec  5 12:32:03 server varnishd[28446]: child (22431) Started
Dec  5 12:32:04 server varnishd[28446]: Child (22431) said Child starts
Dec  5 12:32:04 server varnishd[28446]: Child (22431) said SMF.s0 mmap'ed 268435456 bytes of 268435456

The message above comes from the Varnish Manager. The Manager is the Varnish process (there are two Varnish processes) that monitors and manages the Varnish caching process. Here it’s telling us that caching process has stopped responding back with a PONG to its PING. A ping from the Manager to the Cache process with its response look like this and happens every 3 seconds (at least in this configuration):

    0 CLI          - Rd ping
    0 CLI          - Wr 200 19 PONG 1323181633 1.0
    0 CLI          - Rd ping
    0 CLI          - Wr 200 19 PONG 1323181636 1.0

So going back to the error message, the Manager is telling us that it hasn’t received a “PONG” back from the Cache process in a while. A “while” is controlled by the variable cli_timeout which has a default of 10 seconds in Varnish 3.x and 20 seconds in Varnish 2.x. So the Manager waits for about 10 seconds before it fires a UNIX kill using signal SIGQUIT (signal=3). Next the Manager starts the child back up again afresh.

You may be asking yourself: why is the Cache process not responding? There are a few of possible causes. Either the cache process is deadlocked (deep code issue) or the server is under a very heavy disk IO load / memory shortage. So how do you determine which category you fall under? I recommend checking the load average and memory utilization levels on your server using Sysstat tools.

Did you know?

UNIXy is a fully managed server and cluster provider. What this means is we don’t expect you to know anything about servers or server management. The good news is it doesn’t cost you extra to have us manage your UNIXy server! Get in touch with us here to get the ball rolling!

 

That’s all folks.

Don’t pass on the opportunity to get awarded two owned licenses ($278 value) and a feature on our blog! Submit your artwork for either the cPanel Varnish Plugin or the DirectAdmin Varnish Plugin to isaig@unixy.net.

This release squashes some bugs affecting domain purging on servers running the plugin, licensing, and other minor issues. It’s available for download. The Varnish plugin can be obtained by visiting this page: http://www.unixy.net/varnish

Varnish PHP bindings are useful for folks that need to manage Varnish from PHP. A palpable version of the extension code has finally been released. Keep in mind that the release is early beta. Nonetheless, the milestone is significant. So, what can one accomplish with the API?

Here’s a list of the most important function calls:

 stop
 start
 banUrl - Purge URL
 ban - Free form purge command
 isRunning - Boolean
 setPort - Set the admin port
 getSnapshot - Retrieve statistics snapshots
 getLine - Retrieve log entry

We are keeping a close eye on the development of the PHP Varnish extension and will update this page.

About UNIXY

UNIXY is a long-time Varnish Cache user and evangelist. They have been offering Varnish acceleration to their VPS, dedicated server, and cluster clients for more than three years. They have released the first cPanel Varnish plugin as well as spun a new startup,Fastlayer, the on-demand HTTP accelerator for the cloud.

That’s all folks!