Description of problem:
Invoking a task in a loop causes memory consumption of wsgi:pulp processes slowly growing over time. Particular example when the increase was seen is creating a repo, uploading some RPM unit and deleting the repo - done in a loop. Since the wsgi script shall not depend on particular task type, I deduce the leak is generic and can occur by repetitive invoking any kind of pulp task.


Version-Release number of selected component (if applicable):
Sat 6.2.4
pulp-server-2.8.7.3-1.el7sat.noarch


How reproducible:
100% (in reasonable bigger time)


Steps to Reproduce:
(Satellite reproducer)
1. the reproducer itself:

hammer product create --name=custom_product --organization-id=1 --label=custom_product

while true; do
	date
	sleep 2
	hammer repository create --content-type=yum --download-policy=immediate --label=custom_repo --name=custom_repo --organization-id=1 --product=custom_product
	hammer repository delete --name=custom_repo --organization-id=1 --product=custom_product
done

2. monitor RSS of wsgi:pulp processes (there are multiple, just few of them really do a job and only those will have growing RSS). Example how I collected it:

i=0; while true; do date; ps aux | grep pulp | grep wsgi > ps.pulp.${i}.txt; sleep 300; i=$((i+1)); done

(and monitor it via:

for i in $(grep -v grep ps.pulp.0.txt | awk '{ print $2 }'); do echo $i; cat $(ls ps.pulp.*.txt -tr) | grep "^apache[ ]*$i "; echo; done

)

---
standalone pulp reproducer:

name="some-very-long-repo-name-some-very-long-repo-name-some-very-long-repo-name-test"

i=1;
while true; do
  pulp-admin rpm repo create --repo-id=${name}-${i} --display-name=${name}-${i}
  pulp-admin rpm repo delete --repo-id=${name}-${i} 
  sleep 2
done

(plus some ps monitoring)


Actual results:
RSS grows approx 110bytes per one task  /220bytes per one iteration of above cycle (sum of RSS increases per individual processes)


Expected results:
no RSS growth


Additional info: