GitHub user KoenDG opened a pull request: https://github.com/apache/kafka/pull/3891
[WIP] MINOR: Further code cleanup involving log statements First of all, terribly sorry for not having included this in the previous PR, that one only focused on the streams folder, this one is on the entire project. I realized my mistake too late. I do need some input for this one, I left 2 TODO statements in the code that I'll point out. This commit largely replaces string concatenation with placeholders in debug and trace log statements. Other things I'll point out with comments. For historical purposes, on why replacing string concatenation with placeholders: When running an application on a certain log level, one wants to avoid log statements of more detailed levels actually being evaluated, both due to potential size issues and time spent doing it, since they're not actually going to be printed. If the message being passed to the log method utilizes string concatenation directly in the passed argument, that means the string will be fully evaluated before being passed along to the log method, to then potentially not even be shown, if the application is running on a different log level. Using placeholders prevents this from happening. You can merge this pull request into a Git repository by running: $ git pull https://github.com/KoenDG/kafka logPlaceholders Alternatively you can review and apply these changes as the patch at: https://github.com/apache/kafka/pull/3891.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #3891 ---- commit ae179142dc91ab137eb8f0b3ec606f9a12f36f9f Author: coscale_kdegroot <koen.degro...@coscale.com> Date: 2017-09-18T12:35:26Z WIP, need input on 2 cases in the code. This commit largely replaces string concatenation with placeholders in debug and trace log statements. ---- ---