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--- litespeed_wiki:cloudlinux:lsphp_criu_enable [2019/10/15 18:41]
Lisa Clarke [Enabling CRIU on CloudLinux + cPanel EA4 + LSWS]
+++ litespeed_wiki:cloudlinux:lsphp_criu_enable [2025/05/21 18:40] (current)
Lisa Clarke Redirect to new Documentation Site
@@ Line 1: / Line 1: @@
-====== Enabling CRIU on CloudLinux + cPanel EA4 ======
+~~REDIRECT>https://docs.litespeedtech.com/cp/cpanel/cloudlinux/~~
-**IMPORTANT!! CRIU may cause stability issues! Enable CRIU AT YOUR OWN RISK!**
-Checkpoint/Restore In Userspace, or CRIU, is an open source project which dumps all of the information of a running process to disk and restores it at the point of the dump.  The LiteSpeed Enterprise Edition Web Server now supports CRIU for the CloudLinux implementation of the PHP processor.
-However, generally, we don't recommend you enable CRIU unless you have a special requirement for it. CRIU uses significant server resources and may generate unusual errors while providing no performance benefits.
-**We have received quite a few reports that potential bugs on the CRIU module may cause web server stability issues. Please permanently disable CRIU, or enable CRIU AT YOUR OWN RISK**.
-===== Requirements =====
-  - CloudLinux System
-  - ea-apache24-mod_lsapi 1.1 on cpanel EA4 (or mod_lsapi on cPanel EA3)  or above
-  - LiteSpeed Web Server 5.3 or above.
-===== Installation =====
-==== Verify CRIU is enabled on your system ====
-Criu is installed with dependency to ea-apache24-mod_lsapi for cpanel EA4( or mod_lsapi for cpanel EA3) 1.1 and above package.
-If you have not installed it, you should:
-<code>yum install liblsapi liblsapi-devel</code>
-<code>
-=============================================================================================================================================================================
- Package                                Arch                          Version                                        Repository                                         Size
-=============================================================================================================================================================================
-Installing:
- liblsapi                               x86_64                        1.1-28.el7.cloudlinux                          cloudlinux-x86_64-server-7                        180 k
- liblsapi-devel                         x86_64                        1.1-28.el7.cloudlinux                          cloudlinux-x86_64-server-7                         37 k
-Installing for dependencies:
- crit-lve                               x86_64                        3.7-3.el7                                      cloudlinux-x86_64-server-7                        9.6 k
- criu-lve                               x86_64                        3.7-3.el7                                      cloudlinux-x86_64-server-7                        439 k
- criu-lve-devel                         x86_64                        3.7-3.el7                                      cloudlinux-x86_64-server-7                         11 k
- libnet                                 x86_64                        1.1.6-7.el7                                    cloudlinux-x86_64-server-7                         58 k
- protobuf-c                             x86_64                        1.0.2-3.el7                                    cloudlinux-x86_64-server-7                         27 k
- protobuf-python                        x86_64                        2.5.0-8.el7                                    cloudlinux-x86_64-server-7                        129 k
- python-criu-lve                        x86_64                        3.7-3.el7                                      cloudlinux-x86_64-server-7                        136 k
- python-ipaddr                          noarch                        2.1.11-1.el7                                   cloudlinux-x86_64-server-7                         34 k
-Transaction Summary
-=============================================================================================================================================================================
-Install  2 Packages (+8 Dependent packages)
-</code>
-<code>yum install ea-apache24-mod_lsapi</code>
-Check CRIU whether the service is running or not. \\
-  ps -ef | grep criu
-  root      967641       1  0 19:24 ?        00:00:00 /usr/sbin/criu service -v4 -o /var/log/criu-service.log --address /var/run/criu/criu_service.socket
-  root      967680  965818  0 19:24 pts/1    00:00:00 grep --color=auto criu
-If not, enable by following method:
-<code>
-systemctl enable criu
-systemctl start criu
-systemctl status criu
-</code>
-Output should be ''Active: active (running)''.
-  [root@globalsupport ~]# systemctl status criu
-  ● criu.service - Checkpoint Restore in Userspace daemon
-   Loaded: loaded (/usr/lib/systemd/system/criu.service; disabled; vendor preset: disabled)
-   Active: active (running) since Mon 2018-08-20 19:24:25 UTC; 4min 23s ago
-  Process: 967640 ExecStartPre=/bin/mkdir -p /var/run/criu (code=exited, status=0/SUCCESS)
-  Main PID: 967641 (criu)
-   CGroup: /system.slice/criu.service
-           └─967641 /usr/sbin/criu service -v4 -o /var/log/criu-service.log --address /var/run/criu/criu_service.socket
-  Aug 20 19:24:25 globalsupport.litespeedtech.com systemd[1]: Starting Checkpoint Restore in Userspace daemon...
-  Aug 20 19:24:25 globalsupport.litespeedtech.com systemd[1]: Started Checkpoint Restore in Userspace daemon.
-  Aug 20 19:24:25 globalsupport.litespeedtech.com criu[967641]: Warn  (criu/kerndat.c:660): Can't load /run/criu.kdat
-====CRIU Master Switch on LSWS ====
-CRIU is disabled by default. To enable it, you can go to LSWS Web Admin Console -> Server -> PHP -> PHP Global Configuration -> Enable CRIU( Again, we recommend you keep CRIU off unless you have some speical testing need only).
-{{:litespeed_wiki:cloudlinux:lsws-master-criu-switch.png?800|}}
-==== Check CRIU parameters====
-In CloudLinux, LSPHP have been compiled with CRIU already. Please check [[https://docs.cloudlinux.com/index.html?criu_support.html|here]]   \\
-Use ''phpinfo()'' with parameter ''-DWITH_CRIU'' to check the LSPHP build.
-====Configure the PHP environment====
-Add the following necessary parameter to the PHPx.x **External App > Environment** \\
-<code>
-LSAPI_CRIU=1
-</code>
-Example for PHP56 + Enable CRUI + Set INITIAL\\
-{{:litespeed_wiki:cloudlinux:criu-2.png?|}}
-===Important Syntax===
-^Variable^Values^Default^Description^
-|LSAPI_CRIU|1/On/Off|Off|If set to On, CRIU will be performed. 1=On|
-|LSAPI_INITIAL_START|A number from 1 upwards.|15|The number of consecutive calls which must be made within a single PHP instance before a dump of the instance will be made.  If there’s no PHP instance running and there’s a dump on disk it will be restored on the first use.|
-|LSAPI_CRIU_IMGS_DIR_PATH|Any valid, existing directory|/var/run/lsws/cl_criu/|CRIU images will start from this directory; a subdirectory named "images" will be created below and then a directory for each user's type of request.  There needs to be lots of free space in this file system.|
-|LSAPI_CRIU_DEBUG|On/Off|Off|If set to ''On'', messages concerning CRIU processing will be written to the stderr.log file (usually in /usr/local/apache2/logs/stderr.log)|
-===== How to Verify =====
-====Step 1====
-  - Prepare any PHP site, e.g. WordPress
-====Step 2====
-  - Generate the dump by hitting the WordPress site
-  - Hit more than INITIAL_START number, e.g. 20 times
-  - If an image dump is generated, you should see an image folder under ''/var/run/lsws/cl_criu/''
-====Step 3====
-  - Check the PHP process number by <code>ps -ef | grep php
->>> user      868577  ...   10:54   0:00 lsphpL</code>
-  - Kill the lsphp process via <code>kill -9  868577</code>
-====Step 4====
-  - Restore the PHP by refreshing the WordPress page to regenerate it
-  - Verify the process number is the same as before:<code>ps -ef | grep php
->>> user      868577  ...   10:55   0:00 lsphp</code>The process is **back**!!
-  - You can also check standard error log for something like <code>LSCRIU: Successful CloudLinux dump of PID: 868577
-LSCRIU: Successful CloudLinux restore of PID: 868577, parent: 1.</code>
-===== Logs =====
-  - **Error log** default located at Apache standard error log
-  - ''dump.log'' is in the images directory
-  - ''restore.log'' is in the images directory
-**NOTE**: ''restore.log'' is generated even when there is no dump, so it's expected to see some related fail logs