From ed62339f899e30690f88a4d286a07c417796dbc1 Mon Sep 17 00:00:00 2001
From: Jake Moshenko <jake.moshenko@coreos.com>
Date: Tue, 4 Aug 2015 18:20:54 -0400
Subject: [PATCH] Improve the performance of queue candidate queries.
---
data/queue.py | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/data/queue.py b/data/queue.py
index 60632f5b1..d40df3335 100644
--- a/data/queue.py
+++ b/data/queue.py
@@ -120,16 +120,21 @@ class WorkQueue(object):
name_match_query = self._name_match_query()
running = self._running_jobs(now, name_match_query)
- avail = self._available_jobs_not_running(now, name_match_query, running)
+ avail = self._available_jobs_not_running(now, name_match_query, running).alias('avail')
item = None
try:
- db_item_candidate = avail.order_by(QueueItem.id).get()
+ db_item_candidate_id = (QueueItem
+ .select(avail.c.id)
+ .from_(avail)
+ .order_by(avail.c.id)
+ .tuples()
+ .get())[0]
with self._transaction_factory(db):
still_available_query = (db_for_update(self
._available_jobs(now, name_match_query)
- .where(QueueItem.id == db_item_candidate.id)))
+ .where(QueueItem.id == db_item_candidate_id)))
db_item = still_available_query.get()
db_item.available = False