view mod_log_events_by_memory/README.markdown @ 4651:8231774f5bfd

mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.
author Kim Alvefur <zash@zash.se>
date Sun, 22 Aug 2021 13:22:59 +0200
parents f781a90018f4
children
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This module compares the memory usage reported by Lua before and after
each event and reports it to the log if it exceeds the configuration
setting `log_memory_threshold` (in bytes).

``` lua
log_memory_threshold = 20*1024
```

If you are looking to identify memory leaks, please first read [Three
kinds of memory
leaks](https://blog.nelhage.com/post/three-kinds-of-leaks/).

Prosody runs on Lua which uses automatic memory management with garbage
collection, so the numbers reported by this module are very likely to be
useless for the purpose of identifying memory leaks. Large, but
temporary, increases in memory usage can however highlight other kinds
of performance problems and sometimes even provide hits for where to
look for memory leaks.