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Stage 9 - Upgrade Zookeeper (3.4.8 -> 3.6.3)

Stage 9 - Upgrade Zookeeper (3.4.8 -> 3.6.3)

Objective

Upgrade Apache Zookeeper from the current version 3.4.8 to version 3.6.3.

Prerequisites

  1. syndeia-cloud-3.5.<build-version>_cassandra_zookeeper_kafka_setup.zip media is available.

  2. Ensure previous stages have been completed without error.

  3. Make sure that the Zookeeper service is stopped.

    1. Check using the below command.

      systemctl status zookeeper

      You can verify that it is stopped if, Active: inactive (dead) shows up in the output.

      ● zookeeper.service Loaded: loaded (/etc/systemd/system/zookeeper.service; enabled; vendor preset: enabled) Active: inactive (dead) since Fri 2022-09-09 07:08:09 EDT; 1h 24min ago Main PID: 8865 (code=killed, signal=KILL)

    2. If not stopped, then stop using the below command.

      systemctl stop zookeeper

Steps

If you are on Linux, and connected to the Internet, the below process is automated and can be run via the syndeia-cloud-3.5_zookeeper_pre-setup.bash script included in the syndeia-cloud-3.5. build_version _cassandra_zookeeper_kafka_setup.zip media

Step 1 - Download and extract the new 3.6.3 version of Zookeeper (rename it to be consistent with previous versioned naming)

wget https://archive.apache.org/dist/zookeeper/zookeeper-3.6.3/apache-zookeeper-3.6.3-bin.tar.gz -O zookeeper-3.6.3-bin.tar.gz sudo tar -xzf zookeeper-3.6.3-bin.tar.gz -C /opt/ sudo mv /opt/apache-zookeeper-3.6.3-bin /opt/zookeeper-3.6.3

Step 2 - Copy over logs folder from old ZK version.

sudo cp -R /opt/zookeeper-3.4.8/logs /opt/zookeeper-3.6.3/.

Step 3 - Check for the presence of an /etc/zookeeper/conf/myid file and that it has a single value: its ZK node id.

  • Run the following command:

    cat /etc/zookeeper/conf/myid

  • If the above returns an error, create it as below:

    echo "1" | sudo tee /etc/zookeeper/conf/myid >/dev/null

Step 4 - Add snapshot.trust.empty=true to the end of Apache Zookeeper's config file (/etc/zookeeper/conf/zoo.cfg) to allow startup for initial snapshot creation (see ZOOKEEPER-3056 for more info).

Step 5 - Update symlink.

sudo ln -nfs /opt/zookeeper-3.6.3 /opt/zookeeper-current

Step 6 - Take ownership of the extracted folder & the symlink.

sudo chown -R zookeeper:kafka-zookeeper /opt/zookeeper-current sudo chown -R zookeeper:kafka-zookeeper /opt/zookeeper-3.6.3

Step 7 - Copy in new ZK systemd service file.

sudo cp syndeia-cloud-${SC_version}_cassandra_zookeeper_kafka_setup/conf/init/systemd/zookeeper.service /etc/systemd/system/.

Step 8 - Load the new service file.

sudo systemctl daemon-reload

Step 9 - Start Zookeeper service.

sudo systemctl start zookeeper

Step 10 - Confirm Zookeeper started successfully & there are no errors in the ZK service’s log.

systemctl --type=service --state=active | grep zookeeper sudo systemctl status zookeeper

Step 11 - Stop Zookeeper service.

sudo systemctl stop zookeeper

Step 12 - Edit /etc/zookeeper/conf/zoo.cfg and remove previously added snapshot.trust.empty setting.

Step 13 - Start Zookeeper service

sudo systemctl start zookeeper

Verification

Ensure new version of Zookeeper is running and there are no errors in the journal /log file.