Step 3: Apply the Patch to CLDB Nodes

Apply the patch to CLDB slave nodes prior to applying the patch on the master CLDB node. After you apply a patch to a CLDB node, you must verify that container 1 is fully replicated before proceeding to apply the patch to the next CLDB node.

About this task

For large clusters with many containers, when you do not patch CLDB nodes in the prescribed order, there may be a considerable delay before the cluster can process client operations. For smaller clusters, this is not as critical as the cluster can generally start accepting client operations in about 5 minutes.

Complete the following steps of each CLDB slave node and then on the CLDB master node:

Procedure

Stop the MapR Warden and ZooKeeper (if installed) services:
1. To stop MapR Warden , run the following command:
```
sudo service mapr-warden stop
```
2. If Zookeeper is installed on the node, run this command:
```
sudo service mapr-zookeeper stop
```
If there is already a patch installed on the cluster, run one of the following commands to uninstall it:
- On CentOS/Redhat: sudo rpm -e mapr-patch
- On SUSE: sudo zypper remove mapr-patch
- On Ubuntu: sudo apt-get -y remove mapr-patch
Install the patch using one of the following commands:
- On CentOS/RedHat: sudo rpm -ivh mapr-patch-<new_patch_number>.rpm
- On SUSE: sudo zypper install mapr-patch-<new_patch_number>.rpm
- On Ubuntu: sudo dpkg -i mapr-patch<new_patch_number>.deb
Start the MapR Warden and ZooKeeper (if installed) services:
1. If ZooKeeper is installed on the node, run this command to start ZooKeeper:
```
sudo service mapr-zookeeper start
```
2. To start Warden, run this command:
```
sudo service mapr-warden start
```
To verify that the patch was installed successfully, run one of the following commands:
- On CentOS/Redhat or SUSE: sudo rpm -ql mapr-patch-<new_patch_number>
- On Ubuntu: sudo dpkg -l | grep mapr-patch-<new_patch_number>
Verify that the CLDB node that you patched is running and that container 1 on that node is fully replicated.
Run maprcli dump containerinfo -ids 1 -json.
In the output, the CLDB node that you just patched should be listed under ActiveServers and it should report a VALID state for container 1.
For example:
```
...
      "data":[ 
             { 
                "ContainerId":1, 
                "Epoch":3, 
                "Master":"<masterCLDB_IP>:5660--3-VALID", 
                "ActiveServers":{  
                  "IP:Port":[ 
                      "<masterCLDB_IP>:5660--3-VALID", 
                      "<slaveCLDB_IP>:5660--3-VALID", 
                      "<slaveCLDB_IP>:5660--3-VALID"
                   ] 
              }, 
                  "InactiveServers":{    
                   }, 
                  "UnusedServers":{ 
              },
...
```
NOTE: The RESYNC state will display when container 1 is not fully replicated on that node. You must wait until the CLDB node that you just patched has a VALID state for container 1.
For more information, see dump containerinfo