Exercise - Use Memcached

Standalone

1. install memcached

   sudo yum -y install memcached

2. run memcached

   sudo systemctl start memcached

3. test that memcached is running

   [ghost@pvnp memcached]$ sudo systemctl status memcached
   ● memcached.service - Memcached
      Loaded: loaded (/usr/lib/systemd/system/memcached.service; disabled; vendor preset: disabled)
      Active: active (running) since Tue 2017-11-21 10:29:36 UTC; 11s ago
    Main PID: 2145 (memcached)
      CGroup: /system.slice/memcached.service
              └─2145 /usr/bin/memcached -u memcached -p 11211 -m 64 -c 1024
   
   Nov 21 10:29:36 pvnp systemd[1]: Started Memcached.
   Nov 21 10:29:36 pvnp systemd[1]: Starting Memcached...
   [ghost@pvnp memcached]$

   test that memcached is working

   [ghost@pvnp ~]$ telnet localhost 11211
   Trying ::1...
   Connected to localhost.
   Escape character is '^]'.
   stats items

   But that says nothing on if your publics can connect to the remote server hosting the memcached service ... you can be as restrictive as you like; for now, I am going to add a firewall rule to allow traffic on that port:

   [ghost@pvnp ~]$ sudo firewall-cmd --zone=public --add-port=11211/tcp
   [sudo] password for ghost:
   success
   [ghost@pvnp ~]$ sudo service firewalld restart #-ish

   Now check again, but this time from the server where your public instance/s is/are running:

   test that memcached is working

   ~/Desktop/PUBLICS\-> telnet 45.79.176.97 11211
   Trying 45.79.176.97...
   Connected to li1275-97.members.linode.com.
   Escape character is '^]'.
   stats items

   If you get a connection here, now you know everything is wired properly.

4. Now that memcached is setup and running on some remote server, we need to configure Magnolia (Publics ... in every case, since we've changed a pom file, we have changed the project and need to rebuild and redeploy) to know about it ... stop Magnolia and

   Click here to expand...

   Alter your webapp pom like so:

   <!--
   <dependency>
     <groupId>info.magnolia.eebundle</groupId>
     <artifactId>magnolia-enterprise-pro-webapp</artifactId>
     <type>pom</type>
   </dependency>
   -->
   <dependency>
     <groupId>info.magnolia.cache</groupId>
     <artifactId>magnolia-cache-memcached</artifactId>
     <version>5.5.6</version>
   </dependency>
   <dependency>
     <groupId>info.magnolia.eebundle</groupId>
     <artifactId>magnolia-enterprise-pro-webapp</artifactId>
     <type>pom</type>
     <exclusions>
       <exclusion>
         <groupId>info.magnolia.cache</groupId>
         <artifactId>magnolia-cache-ehcache</artifactId>
       </exclusion>
     </exclusions>
   </dependency>
   <dependency>
     <groupId>info.magnolia.eebundle</groupId>
     <artifactId>magnolia-enterprise-pro-webapp</artifactId>
     <type>war</type>
   </dependency>

   As usual, you should restart Magnolia and see something like this:

   

5. Now let's create entries for /modules/cache/config/contentCaching/*
   Notice from the install you now have /modules/cache/config/cacheFactory/delegateFactories/memcached/caches.
   We need to set this up to reflect where the server is, etc.:
   set /modules/cache/config/cacheFactory/delegateFactories/memcached/caches/defaultPageCache/servers@0 and /modules/cache/config/cacheFactory/delegateFactories/memcached/caches/uuid-key-mapping/servers@0 properly ... mine is 45.79.176.97:11211:

   

   
   

6. Now fire up your Public instances, and let's browse a bit to prime the cache.

   Click here to expand...

   I'm lazy, so I don't browse ... I simply request pages programmatically.  Something like this:

   #!/bin/bash
   
   for i in `seq 1 1`;
   do
   
       curl -u superuser:superuser http://176.58.102.50:8080/magnoliaPublic1/p99.html
   done

   It would be more useful here to use the Travel Demo and prime the cache by iteratively curling over all the pages it comes with.

   
   

   Then a refresh on Author in Tools → Cache Tools gets me this:

   

   Now that you've primed the cache, you can check again to confirm the cache data are being stored remotely:

   ~/Desktop/PUBLICS\-> telnet 45.79.176.97 11211
   Trying 45.79.176.97...
   Connected to li1275-97.members.linode.com.
   Escape character is '^]'.
   stats items
   STAT items:9:number 1
   STAT items:9:age 128
   STAT items:9:evicted 0
   STAT items:9:evicted_nonzero 0
   STAT items:9:evicted_time 0
   STAT items:9:outofmemory 0
   STAT items:9:tailrepairs 0
   STAT items:9:reclaimed 0
   ...
   ...