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| author | Stan Hu <stanhu@gmail.com> | 2018-09-11 22:55:01 -0700 |
|---|---|---|
| committer | Stan Hu <stanhu@gmail.com> | 2018-09-11 23:12:23 -0700 |
| commit | 95e292780492ea764328566503ebefcae8a170f3 (patch) | |
| tree | 3e79f94ded694e27336e059063463e2018cb83c5 | |
| parent | e5b6e8e2550e203978cd25d3e07ca468b4d06c91 (diff) | |
| download | gitlab-shell-95e292780492ea764328566503ebefcae8a170f3.tar.gz | |
Fix newlines not appearing between new log entriessh-fix-nonatomic-puts
In https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/5017, we
observed that lots of log messages were being dropped by Fluentd due to
missing newlines.
This occurs because there is a bug in Ruby where IO#puts calls write() twice:
once to write the main text, and another to write the newline
(https://bugs.ruby-lang.org/issues/14042). In a highly concurrent environment
like GitLab.com, this can lead to interleaved newlines.
A workaround is to use `IO#print` and append the newline ourselves.
Closes https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/5017
| -rw-r--r-- | lib/gitlab_logger.rb | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/gitlab_logger.rb b/lib/gitlab_logger.rb index ed169f7..67f6030 100644 --- a/lib/gitlab_logger.rb +++ b/lib/gitlab_logger.rb @@ -68,9 +68,10 @@ class GitlabLogger case log_format when 'json' - log_file.puts format_json(data) + # Don't use IO#puts because of https://bugs.ruby-lang.org/issues/14042 + log_file.print("#{format_json(data)}\n") else - log_file.puts format_text(data) + log_file.print("#{format_text(data)}\n") end end |