Hi Zach, thank you for this request. Having reviewed it I think it is going to make for a challenging SRU due to the size and complexity of the patch (and the fact that it is point release rather than a single fix). I wonder if it is possible to isolate a single fix that would resolve the issue you see so that we can SRU that instead? As an alternative I have been discussing other ways that we might be able to get this done and wanted to propose the solution of backporting the version in Noble (currently 23.2.0-2) to the Carcal Ubuntu Cloud Archive that way we would have the same version in Noble made available to users of Jammy running OpenStack Caracal and avoid having to change the version in Jammy itself. The process of doing the backport is fairly simple (i can show you how) but it is going to require thorough testing to ensure (a) no regressions are introduced and (b) the desired performance is achieved. Can you please let me know your thoughts?
-- You received this bug notification because you are a member of Debcrafters packages, which is subscribed to python-attrs in Ubuntu. https://bugs.launchpad.net/bugs/2121607 Title: [SRU] Nova-api showing latency after upgrading to Caracal Status in OpenStack Compute (nova): Confirmed Status in python-attrs package in Ubuntu: In Progress Status in python-attrs source package in Jammy: In Progress Bug description: [ Impact ] * A resource leak bug in 21.2.0 of python-attrs (<https://github.com/python-attrs/attrs/issues/826>) caused performance issues when an application created many classes with the same name. * This caused a performance regression in nova through its dependency on python-jsonschema * The latency of API calls to nova increases over time [ Test Plan ] To reproduce the issue and confirm the fix: * Create a minimal openstack deployment, using e.g. devstack (<https://docs.openstack.org/devstack/latest/>). * Run a script which makes many calls to the nova API ---Script to call API--- #!/bin/bash # --- Get a fresh token (requires openrc sourced first) --- get_token() { openstack token issue -f value -c id } OS_TOKEN=$(get_token) echo "Using token: $OS_TOKEN" # --- Send requests at 10 per second --- COUNT=0 while true; do COUNT=$((COUNT + 1)) STATUS=$(curl -s -o /dev/null -w "%{http_code}" \ -H "X-Auth-Token: $OS_TOKEN" \ -H "Accept: application/json" \ "$NOVA_URL/servers/detail") echo "$(date +'%F %T') [$COUNT] HTTP $STATUS" if [ "$STATUS" = "401" ]; then echo "[$(date)] Got 401 → refreshing token..." OS_TOKEN=$(get_token) continue # retry next loop with fresh token fi # sleep 0.1 # 0.1 sec → 10 per second done ---/Script to call API--- * Simultaneously monitor the response time of API calls using the openstack CLI ---Script to monitor response time--- #!/bin/bash # --- Again openrc must be sourced first --- os_quota() { openstack quota list --compute --timing --format=json } headers() { os_quota | grep -o -P '/(\w|\d){32}(/d)?' | tr '\n' ',' } time_api() { os_quota | awk 'BEGIN { FS=","; ORS=","} /quota/ {print $2} END { printf "\n" }' } OUTPUT="api_calls_$(date +%Y-%m-%dT%H_%M_%S)" echo -n "# time," >>"$OUTPUT" headers >>"$OUTPUT" echo >>"$OUTPUT" i=0 while true; do echo -n "$(date +'%F %T')," >>"$OUTPUT" time_api >>"$OUTPUT" echo -n "." if ((i > 80)); then i=0 echo fi sleep 5 done ---/Script to monitor response time--- * Observe that the response time increases over time with python-attrs 21.2.0 * I did this over a period of about 20 hrs. * Log in to the server hosting the nova API and upgrade python-attrs to 21.4.0 * Repeat the above steps and observe that the response time remains stable over time. [ Where problems could occur ] * Other packages depend on python-attrs as a library and so could be affected. * From 21.2.0 to 21.4.0 there was one backward incompatible change change of which could potentailly cause issues: * <https://github.com/python-attrs/attrs/blob/21.4.0/CHANGELOG.rst> """ When using @define, converters are now run by default when setting an attribute on an instance -- additionally to validators. I.e. the new default is on_setattr=[attrs.setters.convert, attrs.setters.validate]. This is unfortunately a breaking change, but it was an oversight, impossible to raise a DeprecationWarning about, and it's better to fix it now while the APIs are very fresh with few users. """ * Since there are no version pins of python-attrs excluding this version it is unlikely to break other packages. * It is possible that some users could be using the python3-attr package in their own code, but it is much more likely that for user code, attr would be installed via pip, either directly or within a virtualenv. * The version in noble is 23.2.0 which already includes all these changes and there doesn't seem to be any associated issues. [ Other Info ] * This SRU proposal bumps to 21.4.0 instead of 21.3.0 because 21.4.0 is a bug fix release for a regression in 21.3.0. * This is the first ubuntu specific modification to this package, but it is a fairly minor one and doesn't need to be carried forward to any other series. * A possible lighter weight alternative is to simply cherry pick the bugfix commit <https://github.com/python- attrs/attrs/commit/38580632ceac1cd6e477db71e1d190a4130beed4> To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/2121607/+subscriptions -- Mailing list: https://launchpad.net/~debcrafters-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~debcrafters-packages More help : https://help.launchpad.net/ListHelp
