Скачать или смотреть Fixing Elasticsearch 7.7 Cluster Time-Out Issues

Discover how to resolve the `Elasticsearch` 7.7 time-out issue when joining a cluster and ensure seamless cluster operations.
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Solving Elasticsearch 7.7 Cluster Time-Out Issues

If you're working with Elasticsearch and trying to build a cluster, you might have encountered a frustrating problem: nodes failing to join the cluster due to time-out errors. This kind of issue can halt your progress and cause considerable frustration, especially when it was functioning properly before.

In this guide, we'll take a closer look at the problem, analyze the potential causes, and provide a detailed solution. By the end, you'll be equipped with the knowledge to troubleshoot and fix your cluster's time-out issues swiftly.

Understanding the Problem

When adding nodes to your Elasticsearch cluster, you might see logs indicating:

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Such messages usually indicate that the node (in this case, kn-log-02) could not join due to a time-out when validating the join request sent to the master node (kn-log-01). It raises red flags about either network issues or cluster configuration settings.

Key Indicators

Both master and data nodes should have their configurations aligned correctly.

Firewalls should allow communication on necessary ports (9200, 9300).

Ensure that the nodes are alive and in a running state.

Steps Taken to Troubleshoot

When resolving this issue, the following checks and actions were performed:

Firewall Settings: Ensured that communication ports (9200 for REST and 9300 for transport) were not being blocked by the firewall settings.

Rebooting Nodes: Restarted all the machines that comprise your Elasticsearch cluster.

Data Cleanup: Wiped data folders for Elasticsearch and restarted services to ensure a clean state.

These methods are standard practices, yet they didn't yield results in this scenario.

Configurations Reviewed

Check the configurations in your elasticsearch.yml files for both master and data nodes. Here’s a summary:

Master Node Configuration

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Data Node Configuration

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Both configurations match the necessary structure for a cluster to operate smoothly.

Uncovering the Solution

After extensive checking, the root cause of the time-out issue was linked to a physical network problem. Specifically, the MTU (Maximum Transmission Unit) of the Ethernet card was configured with a value that the hardware did not support. This misconfiguration led to packet losses and, consequently, time-out errors.

Steps to Fix the MTU Issue

Identify the MTU Setting: Check your Ethernet card's MTU configuration using network diagnostic tools.

Set the Correct MTU: Reconfigure the MTU to a value that is appropriately supported by your hardware. Common values are typically set to 1500, but can vary based on the network specifications.

Restart Network Services: After adjusting the MTU settings, restart your network interfaces or the entire machine for the changes to take effect.

Verify Cluster Status: Use the following command to check the cluster status:

[[See Video to Reveal this Text or Code Snippet]]

With these adjustments, the cluster should re-establish connection, allowing the nodes to join without timing out.

Conclusion

Network configurations can often lead to perplexing issues when setting up Elasticsearch clusters. By meticulously verifying network settings, especially MTU configurations, you'll save yourself hours of debugging.

Should you find yourself in a similar pickle, remember to reassess not just your configurations but also the physical network layer. With the right adjustments, your Elasticsearch 7.7 cluster can thrive without interruptions.

If you have further questions or additional troubleshooting tips, feel free to share them in the comments!