hubble-cli: prevent empty strings in colorer escape sequences to fix excessive cpu usage#44119
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tklauser merged 1 commit intocilium:mainfrom Feb 18, 2026
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/test |
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@chancez This small pull request is waiting for a review from you. |
chancez
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Feb 17, 2026
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@tporeba You'll need to address the CI failures before we can merge :) |
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Add additional empty string checks to the code generating colorer escape sequences. Empty strings in sequences were misinterpreted and caused a lot of unnecessary string replace calls in terminalEscaperWriter increasing CPU usage significantly under high load. Fixes cilium#42564 Signed-off-by: Tomasz Poręba <tporeba@gmail.com>
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I see that tklauser did that before I noticed. Thank you :) |
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@pchaigno @tklauser Could you please add necessary labels to this PR, so this gets backported to versions 1.17, 1.18, 1.19? But I don't have necessary permissions to do that myself. |
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@tporeba I've added the labels for backporting to all supported versions. The regression is severe enough and the patch simple enough that I think we can argue for backporting to v1.18 and v1.17. |
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// no, thank you :)
This PR adds additional empty string checks to the colorer
sequences()func responsible for generating color escape sequences.A bug in this func caused non-empty list of sequenced being generated for cases when coloring was expected to be disabled - there was an empty string returned in the array in such cases. Those empty strings were misinterpreted and caused a lot of unnecessary string replace calls in
terminalEscaperWriter, increasing CPU usage ofhubble observecommand significantly under high load.Fixes: #42564