Flask-Session uses Cachelib for filesystem session storage
A Flask based webapp was tested with Apache Benchmark tool, sending 1000 requests with concurrency 100.
After approx. 500 requests, apache logs start being flooded with warnings like this:
[Wed Mar 20 19:03:07.814067 2024] [wsgi:error] [pid 23776] [client 10.0.11.184:45501] Traceback (most recent call last):
[Wed Mar 20 19:03:07.814068 2024] [wsgi:error] [pid 23776] [client 10.0.11.184:45501] File "/usr/local/lib/python3.8/site-packages/cachelib/file.py", line 122, in _remove_expired
[Wed Mar 20 19:03:07.814069 2024] [wsgi:error] [pid 23776] [client 10.0.11.184:45501] expires = struct.unpack("I", f.read(4))[0]
[Wed Mar 20 19:03:07.814071 2024] [wsgi:error] [pid 23776] [client 10.0.11.184:45501] struct.error: unpack requires a buffer of 4 bytes
To reproduce use Flask-Session in a web app
then test it with
ab -n 1000 -c 100 http://web-app.addr
and check error logs
Environment:
Python version: 3.8
CacheLib version: 0.12.0
Centos version 7.7
Flask-Session 0.3.2
Not sure, but may be ulimit for open files is affecting
su - apache -s /bin/bash -c 'ulimit -Ha' | grep 'open files'
open files (-n) 4096
su - apache -s /bin/bash -c 'ulimit -Sa' | grep 'open files'
open files (-n) 1024
Flask-Session uses Cachelib for filesystem session storage
A Flask based webapp was tested with Apache Benchmark tool, sending 1000 requests with concurrency 100. After approx. 500 requests, apache logs start being flooded with warnings like this:
To reproduce use Flask-Session in a web app then test it with
ab -n 1000 -c 100 http://web-app.addrand check error logs
Environment:
Not sure, but may be ulimit for open files is affecting