Troubleshoot and resolve common problems

Resolve common Redis Data Integration problems

Learn how to diagnose common problems during installation and runtime of Redis Data Integration (RDI).

Problems during installation

Problems with pip

Problems with pip installation can occur because of the following reasons:

• Wrong Python 3 version

  In many Linux distributions, the Python 3 version is still 3.6. You can check this by running: python --version. You want version 3.7 or greater.

• More than one Python 3 version installed

  To solve this problem, create a Python virtual environment (venv) specifying the path to the appropriate Python 3 installation. For example, <PATH>/python3.8 -m venv <VENV-NAME>. If you are not sure about the path run which python3 and copy the path pointing to a Python installation with a version of 3.7 or greater.

• Outdated pip version

  Some old pip versions can have problems with the wheel filename. It is best to update pip as well. In you venv run pip install --upgrade pip.

• Old RDI CLI libraries from previous installations

  Sometimes RDI CLI libraries or its dependencies are already installed and they need an upgrade to get the latest version:

  # outputs the list of installed packages
  pip freeze > requirements.txt
  # updates all packages
  pip install -r requirements.txt --upgrade
  

Problems with the create command

The following problems can occur when running the create command:

• No network access to the Redis Enterprise API

  • Verify your CLI host can resolve the DNS entry you use (if applicable) dig <HOSTNAME>.
  • Verify you have access to the specified ip:port telnet <IP ADDRESS OF SERVER PC> <PORT>.

• Using a Redis Enterprise user with the wrong role

  Users must have roles of either DB Member, Cluster Member, or Admin.

• Trying to connect to the RDI database without an Ingress Controller path

  When running Redis Enterprise on Kubernetes, each Redis database has a service that is created only after the database has been created. To connect with the CLI from outside of Kubernetes and configure the RDI database, you need an Ingress resource for your RDI database and Ingress Controller running on the Kubernetes cluster.

  A Kubernetes Service and Ingress are mutually exclusive. So if your database has a Service you should remove it and add an Ingress resource. Read Kubernetes docs for more information. Alternatively, run the CLI within the Kubernetes cluster as described in Running on Kubernetes.

Problems running Debezium

Set the log level to DEBUG to get more detailed information that would be useful in diagnosing unexpected behavior.

In the application.properties configuration file, add or modify:

quarkus.log.level=DEBUG

The most common problems with running Debezium Server are:

• Debezium failing to reach the configuration file

  The error message for this one is not clear, and typically Debezium reports it couldn't find the first element in the configuration file. Usually it implies there is no application.properties file in $PWD/debezium. Make sure you run the docker run command from the correct directory.

• Debezium failing to reach the source database

  The error message for this situation is also not obvious. Debezium will typically report a problem with reading the binary log of the source database. There are several potential reasons here:

  • The database is not configured to accept external connections. Consult the database specific Debezium documentation:
    • MySQL/MariaDB
    • Oracle
    • PostgreSQL
    • SQL Server
  • There is a local firewall on the Debezium/Database host, or a firewall rule on the subnet. Because you can not run telnet <DB_HOST> <DB_PORT> from the Debezium container, run it from the host. Check the following links to learn how to configure different databases to accept external connections:
    • MySQL/MariaDB
    • Oracle
    • PostgreSQL
    • SQL Server

• Handling a Debezium container crash

  The Debezium Server is stateless. In case it crashes, you can always remove it safely and run a new one using a fixed application.properties file:

  • Check the status of the Debezium Server container:

    run docker ps -a to show all existing containers on the host.

  • If there is a Debezium Server container that has exited, you can remove it using docker rm -f <DEBEZIUM_CONTAINER_ID>.

• Stopping and starting Debezium Server

  In case you want to fix something in the Debezium Server configuration and Debezium Server is still running:

  • Use docker stop <DEBEZIUM_CONTAINER_NAME>.
  • You can start it later using docker start <DEBEZIUM_CONTAINER_NAME>. If You want the container to be attached to the terminal, run it with --attach.

Getting Debezium Server logs

Containerized deployment

• To follow the Debezium Server log output, run:

  docker logs <DEBEZIUM_CONTAINER_NAME> --follow
  

• To get the last COUNT lines of the Debezium Server log, run:

  docker logs <DEBEZIUM_CONTAINER_NAME> -n <COUNT>
  

• To get the log messages generated after a given timestamp, run:

  docker logs <DEBEZIUM_CONTAINER_NAME> --since <TIMESTAMP>
  

• To get the log messages issued before a given timestamp, run:

  docker logs <DEBEZIUM_CONTAINER_NAME> --until <TIMESTAMP>
  

Note: For the format of the TIMESTAMP argument, see the Docker logs documentation.

Examples

• Get the log messages generated after 2023-01-23T10:10:27Z:

  docker logs --since 2023-01-23T10:10:27Z <DEBEZIUM_CONTAINER_NAME>
  

• Get the log messages generated before 2023-01-23T12:55:37Z:

  docker logs --until  2023-01-23T12:55:37Z <DEBEZIUM_CONTAINER_NAME>
  

• Get the log messages generated in the last 50 minutes:

  docker logs --since=50m <DEBEZIUM_CONTAINER_NAME>
  

Redirecting output to a file

If you want to save the log output in a file, add | tee <LOG_FILE_PATH> to the docker logs command. For example:

docker logs <DEBEZIUM_CONTAINER_NAME> -n 10 | tee /home/debezium-server/logs/debezium.log

The last 10 lines of the Debezium Server log will be redirected to standard output and to the file /home/debezium-server/logs/debezium.log.

Non-containerized deployment

The Debezium log files will be created in the directory set for the property <quarkus.log.file.path>.

Example

quarkus.log.file.path=/home/debezium-server/logs/debezium.log
quarkus.log.file.rotation.max-file-size=100M
quarkus.log.file.rotation.file-suffix=.yyyy-MM-dd.gz
quarkus.log.file.rotation.max-backup-index=3
quarkus.log.file.rotation.rotate-on-boot=true

With this configuration:

• A debezium.log file is created in the directory /home/debezium-server/logs/.
• When the log file size reaches 100M it is renamed to debezium.log.2023-01-22.1.gz, and a new log file, debezium.log, is created.
• If the size of the log file reaches 100M and there are already 3 backup log files, the first backup file, debezium.log.2023-01-22.1.gz, is deleted.
• At any point in time, only four log files exist. Three backup log files: debezium.log.2023-01-22.1.gz, debezium.log.2023-01-22.2.gz, debezium.log.2023-01-22.3.gz, and one active log file, debezium.log.