The loggingClassName field is static, creates memory leak and logging inconsistency.

[imreh-zoltan]

Driver version

9.2.1.jre8

SQL Server version

Microsoft SQL Server 2017 (RTM-CU24) (KB5001228) - 14.0.3391.2 (X64) Apr 28 2021 10:32:18 Copyright (C) 2017 Microsoft Corporation Standard Edition (64-bit) on Windows Server 2016 Standard 10.0 (Build 14393: ) (Hypervisor)

Client Operating System

Windows Server 2016

JAVA/JVM version

OpenJDK 64-Bit Server VM, 1.8.0_232-b18

Table schema

Problem description

In com.microsoft.sqlserver.jdbc.SQLServerConnection the field loggingClassName is private static.

The class constructor bellow appends a new connection id to this static field every time a new instance is constructed. This used with the SQLServerConnectionPoolDataSource creates over time a huge string of few MBs and the logging is inconsistent, because the connection cannot be identified. Please make these fields none static in order to remove this issue.

private static String loggingClassName = "com.microsoft.sqlserver.jdbc.SQLServerConnection:";

SQLServerConnection(String parentInfo) throws SQLServerException {
int connectionID = nextConnectionID(); // sequential connection id
traceID = "ConnectionID:" + connectionID;
loggingClassName += connectionID;
if (connectionlogger.isLoggable(Level.FINE))
connectionlogger.fine(toString() + " created by (" + parentInfo + ")");
initResettableValues();

    // Caching turned on?
    if (!this.getDisableStatementPooling() && 0 < this.getStatementPoolingCacheSize()) {
        prepareCache();
    }
}

Consider doing this within the DataSource implementations as well, where there is no memory leak, put it is still inconsistent because of the static field.

Regards,
Zoltan Imreh

[lilgreenbird]

hi @imreh-zoltan

this has been fixed in PR #1633, please upgrade to the latest 9.4.0 release.

[lilgreenbird]

closing as this had been resolved. Please feel free to request re-opening if you have more questions.