* Python-Rpy2 performance issues with genenetwork2

At one point, genenetwork2 was down. A possible cause was that it
wrote into the log file in an infinite loop due to rpy2(v3.4.4), so a
solution was to empty it. Currently, as a work around, rpy2 is
disabled by removing it's imports. This affects WGCNA/ CTL imports and
commenting out Biweight Midcorrelation option in the trait page. See:

- [[https://github.com/genenetwork/genenetwork2/commit/1baf5f7611909c651483208184c5fbf7d4a7a088][1baf5f7]]
- [[https://github.com/genenetwork/genenetwork2/commit/afee4d625248565857df98d3510f680ae6204864][afee4d6]]
- [[https://github.com/genenetwork/genenetwork2/commit/c458bf0ad731e5e5fd9cbd0686936b3a441bae63][c458bf0]]
- [[https://github.com/genenetwork/genenetwork2/commit/d31f3f763471b19559ca74e73b52b3cb5e7153ce][d31f3f7]]

** Reproducing the problem

I went back to commit #b8408cea. With regards to logs, I never
experienced any log issue. Perhaps it's because of how I start my
server:

: env SERVER_PORT=5004 TMPDIR=/home/bonface/tmp WEBSERVER_MODE=DEBUG LOG_LEVEL=DEBUG GENENETWORK_FILES=/home/bonface/data/genotype_files/ GN2_PROFILE=/home/bonface/opt/python3-genenetwork2 ./scripts/run_debug.sh

However, when loading the homepage, I occasionally ran into this trace:

#+begin_src
DEBUG:wqflask.views:.check_access_permissions: @app.before_request check_access_permissions
DEBUG:wqflask.views:.shutdown_session: remove db_session
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: Error: ignoring SIGPIPE signal

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: In addition:
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: Warning messages:

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: 1:
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: In (function (package, help, pos = 2, lib.loc = NULL, character.only = FALSE,  :
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:  library '/home/bonface/R/x86_64-unknown-linux-gnu-library/4.0' contains no packages

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: 2:
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: In (function (package, help, pos = 2, lib.loc = NULL, character.only = FALSE,  :
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:  library '/home/bonface/R/x86_64-unknown-linux-gnu-library/4.0' contains no packages

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: Fatal error: unable to initialize the JIT


WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:
 *** caught segfault ***

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: address (nil), cause 'memory not mapped'

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:
Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace

Selection:

#+end_src

This blocks the flask service. Seems to be related to: [[https://github.com/rpy2/rpy2/issues/769][rpy2-issue#769]]
and [[https://github.com/rpy2/rpy2/issues/809][rpy2-issue#809]]. I tried to reproduce this problem using some endpoint:

#+begin_src python
@app.route("/test")
  def test():
      from rpy2 import robjects as ro
      from rpy2 import rinterface
      from threading import Thread

      def rpy2_init_simple():
          rinterface.initr_simple()

      thread = Thread(target=rpy2_init_simple)
      thread.start()
      return "This is a test after importing rpy2"
#+end_src

which generates this trace:

#+begin_src
/home/bonface/opt/python3-genenetwork2/lib/python3.8/site-packages/rpy2/rinterface.py:955: UserWarning: R is not initialized by the main thread.
              Its taking over SIGINT cannot be reversed here, and as a
              consequence the embedded R cannot be interrupted with Ctrl-C.
              Consider (re)setting the signal handler of your choice from
              the main thread.
warnings.warn(
DEBUG:wqflask.views:.shutdown_session: remove db_session

#+end_src

Modifying the endpoint to:

#+begin_src python
@app.route("/test")
  def test():
      import wqflask.correlation.show_corr_results
      import wqflask.ctl.ctl_analysis
      import time
      from wqflask.correlation.correlation_functions import cal_zero_order_corr_for_tiss

      print("Sleeping for 3 seconds")
      time.sleep(3)
      return "This is a test after importing rpy2"
#+end_src

and refreshing the page a couple of times, I get:

#+begin_src
DEBUG:wqflask.views:.check_access_permissions: @app.before_request check_access_
permissions
Sleeping for 3 seconds
DEBUG:wqflask.views:.shutdown_session: remove db_session
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: Error: ignoring SIGPI
PE signal

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: In addition:
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: Warning messages:

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: 1:
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: In (function (package
, help, pos = 2, lib.loc = NULL, character.only = FALSE,  :
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:  library '/home/bonfa
ce/R/x86_64-unknown-linux-gnu-library/4.0' contains no packages

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: 2:
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: In (function (package
, help, pos = 2, lib.loc = NULL, character.only = FALSE,  :
WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:  library '/home/bonfa
ce/R/x86_64-unknown-linux-gnu-library/4.0' contains no packages

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:
\*** caught segfault ***

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]: address (nil), cause
'memory not mapped'

WARNING:rpy2.rinterface_lib.callbacks:R[write to console]:
Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace

Selection: [2021-06-16 13:11:00 +0300] [18657] [INFO] Handling signal: winch
[2021-06-16 13:11:00 +0300] [18657] [INFO] Handling signal: winch
[2021-06-16 13:13:02 +0300] [18657] [INFO] Handling signal: winch
#+end_src

However, this seems to be non-deterministic, in the sense that I can't
really pin what causes the above. I've tried to write a Locust Test
that simulates users hitting that endpoint:

#+begin_src python
"""Load test a single trait page"""
from locust import HttpUser, task, between


  class LoadTest(HttpUser):
      wait_time = between(1, 2.5)

      @task
      def fetch_trait(self):
          """Fetch a single trait"""
          self.client.get("/test")
#+end_src