Job timeout doesn't kill the mysql query (#4629)

* forward timeout SIGALRMs to MySQL threads in order to kill any running proccesses

* no need to attach to SIGALRM as RQ already does that

redash/query_runner/mysql.py

@@ -14,6 +14,7 @@
 )
 from redash.settings import parse_boolean
 from redash.utils import json_dumps, json_loads
+from redash.tasks.worker import JobTimeoutException
 
 try:
     import MySQLdb
@@ -150,11 +151,13 @@ def _get_tables(self, schema):
 
         return list(schema.values())
 
+
     def run_query(self, query, user):
         ev = threading.Event()
         thread_id = ""
         r = Result()
         t = None
+
         try:
             connection = self._connection()
             thread_id = connection.thread_id()
@@ -164,6 +167,10 @@ def run_query(self, query, user):
             t.start()
             while not ev.wait(1):
                 pass
+        except JobTimeoutException as e:
+            self._cancel(thread_id)
+            t.join()
+            raise e
         except (KeyboardInterrupt, InterruptException):
             error = self._cancel(thread_id)
             t.join()

redash/tasks/worker.py

@@ -4,7 +4,7 @@
 import time
 from rq import Worker as BaseWorker, Queue as BaseQueue, get_current_job
 from rq.utils import utcnow
-from rq.timeouts import UnixSignalDeathPenalty, HorseMonitorTimeoutException
+from rq.timeouts import UnixSignalDeathPenalty, HorseMonitorTimeoutException, JobTimeoutException
 from rq.job import Job as BaseJob, JobStatus