Diagnosing and Resolving SSL SYSCALL Errors in PostgreSQL with Patroni

Problem:

The client reported an intermittent issue with their PostgreSQL database managed by Patroni. The error message encountered was “SSL SYSCALL error: EOF detected”. Despite checking the PostgreSQL logs and HAProxy logs, no corresponding errors were found. The client attempted to change the idle_in_transaction_session_timeout parameter from 1 hour to unlimited, but the error persisted.

Solution:

Upon receiving the issue, the expert sought additional information to diagnose the problem accurately. Key questions were asked to understand the frequency and pattern of the error, recent system changes, other error messages, and the network setup. The client confirmed the use of PostgreSQL 13 with Patroni.

Steps Undertaken:

1. Patroni Logs Review:

• The expert recommended checking the Patroni logs for any errors or warnings related to SSL or network connectivity. This would help determine if the issue was being managed correctly by Patroni.

2. SSL Configuration Check:

• The SSL configuration on both the PostgreSQL server and the client application was examined. This included verifying the validity of certificates and ensuring the compatibility of encryption algorithms.

3. Network Connectivity Analysis:

• The client was advised to check the network connectivity between the PostgreSQL server and the client application using tools like ping or traceroute. This step aimed to identify any packet loss or high latency issues.

4. PostgreSQL Configuration Review:

• A thorough review of PostgreSQL settings related to SSL and network connections was conducted. Important parameters such as ssl_ciphers, ssl_cert_file, ssl_key_file, max_connections, and max_worker_processes were checked.

After following the expert’s recommendations, the client was able to identify and resolve the root cause of the issue. The structured approach helped in systematically narrowing down potential causes and addressing the problem effectively.

Conclusion:

By systematically investigating the issue through log reviews, SSL configuration checks, network analysis, and PostgreSQL settings evaluation, the client successfully resolved the “SSL SYSCALL error: EOF detected” error. This case highlights the importance of a structured troubleshooting approach in diagnosing and resolving complex database connectivity issues.