[LOG4J2-3170] EncodingPatternConverter CRLF encoding is slow with large log messages (it has quadratic time complexity)

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.14.1
• Fix Version/s: 2.15.0
• Component/s: Pattern Converters
• Assignee: Volkan Yazici
• Reporter: Gareth Daniel Smith
• Created: 28/Sep/21 13:04
• Updated: 07/Oct/21 23:07
• Resolved: 03/Oct/21 20:20

Description

This code that escapes newlines is very slow on large log messages where those message contain lots of newline characters. For example "abc" repeated a million times takes less than a second to log, but "a\r\n" repeated a million times takes over 5 minutes (in my test).

I think it is accurate to say that this code has quadratic time complexity: https://github.com/apache/logging-log4j2/blame/master/log4j-core/src/main/java/org/apache/logging/log4j/core/pattern/EncodingPatternConverter.java#L151

If necessary I can supply more examples and/or a fix.

Issue Links

• links to: GitHub Pull Request #585