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--- litespeed_wiki:cloudlinux:lsphp_criu_enable [2018/05/11 12:14]
Eric Leu [How to Verify]
+++ litespeed_wiki:cloudlinux:lsphp_criu_enable [2018/05/15 15:01]
Eric Leu [Step 4]
@@ Line 1: / Line 1: @@
-====== How to enable CRIU ======
+====== How to Enable LSPHP CRIU on CloudLinux ======
-===== Summary =====
+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 both natively, and for the CloudLinux/Apache-specific implementation of the PHP processor.  This will improve the performance of LiteSpeed for transactions which are commonly used, and reduce the memory overhead on the server.
-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 both natively, and for the CloudLinux/Apache specific implementation for the PHP processor.  This will improve the performance of Litespeed for transactions which are commonly used and reduce the memory overhead on the server.
+===== Requirements =====
-===== Must =====
-  - Running as the root user to use CRIU Litespeed or Apache. The CRIU facility requires Litespeed run as the root user to perform the snapshot and recovery. Running as a non-root user automatically disables CRIU.
   - CloudLinux System
+  - LiteSpeed must be running as the root user to use CRIU Litespeed or Apache. Root is required in order to perform the snapshot and recovery. Running as a non-root user automatically disables CRIU.
 ===== Installation =====
-==== 1. CRIU enabled from System ====
-Login your Linux system. Check CRIU service is running or not. \\
+==== 1. Verify CRIU is enabled on your system ====
-If not, enable by following method \\
+Log into your Linux system. Check CRIU whether the service is running or not. \\
+If not, enable by following method:
 <code>
 systemctl enable criu
@@ Line 19: / Line 18: @@
 systemctl status criu
 </code>
-Output **''Active: active (running)''**
+Output should be ''Active: active (running)''.
-====2. CRIU parameter check====
+====2. Check CRIU parameters====
-Generally PHP should be compiled with criu already.   \\
+Generally PHP should be compiled with CRIU already.   \\
-Through ''phpinfo()'' to check LSPHP build with parameter: ''-DWITH_CRIU''.
+Use ''phpinfo()'' with parameter ''-DWITH_CRIU'' to check the LSPHP build.
 If you want to manually compile, please download LSAPI from [[https://www.litespeedtech.com/open-source/litespeed-sapi/download | here ]]
-====3. php env config====
+====3. Configure the PHP environment====
-Add following necessary parameter to the PHPx.x External App -> Environment \\
+Add the following necessary parameter to the PHPx.x **External App > Environment** \\
 <code>
 LSAPI_CRIU=1
@@ Line 35: / Line 34: @@
 {{:litespeed_wiki:cloudlinux:criu-2.png?|}}
-====Important Syntax====
+===Important Syntax===
 ^Variable^Values^Default^Description^
 |LSAPI_CRIU|1/On/Off|Off|If set to On, CRIU will be performed. 1=On|
@@ Line 43: / Line 42: @@
 ===== How to Verify =====
-**Step 1** \\
+====Step 1====
-  - Prepare any php site, e.g. WordPress
+  - Prepare any PHP site, e.g. WordPress
+====Step 2====
-**Step 2** \\
   - Generate the dump by hitting the WordPress site
   - Hit more than INITIAL_START number, e.g. 20 times
-  - If image dump generated, you should see an image folder under ''/var/run/lsws/cl_criu/''
+  - If an image dump is generated, you should see an image folder under ''/var/run/lsws/cl_criu/''
-**Step 3** \\
+====Step 3====
-  - Check PHP process number by \\ ''ps -ef | grep php'' \\ ''>>> user      868577  ...   10:54   0:00 lsphp''
+  - Check the PHP process number by <code>ps -ef | grep php
-  - Kill the lsphp process \\ ''kill -9  868577''
+>>> user      868577  ...   10:54   0:00 lsphpL</code>
-**Step 4** \\
+  - Kill the lsphp process via <code>kill -9  868577</code>
-  - To restore the PHP by refreshing the WordPress page to regenerate it
+====Step 4====
-  - Verify the process number is same as before \\ ''ps -ef | grep php'' \\ ''>>> user      868577  ...   10:55   0:00 lsphp'' \\ Process is **back**!!
+  - Restore the PHP by refreshing the WordPress page to regenerate it
-  - You can also check standard error log \\ ''LSCRIU: Successful CloudLinux dump of PID: 868577'' \\ ''LSCRIU: Successful CloudLinux restore of PID: 868577, parent: 1.''
+  - 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 locate at Apache standard error log
+  - **Error log** default located at Apache standard error log
-  - **dump.log** is in the images directory
+  - ''dump.log'' is in the images directory
-  - **restore.log** is in the images directory
+  - ''restore.log'' is in the images directory
-  * restore.log will gets generated even though there is no dump, so it's expected to see some related fail logs
+**NOTE**: ''restore.log'' is generated even when there is no dump, so it's expected to see some related fail logs