/usr/share/pyshared/pgq/ticker.py is in skytools 2.1.12-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | """PgQ ticker.
It will also launch maintenance job.
"""
import sys, os, time, threading
import skytools
from maint import MaintenanceJob
__all__ = ['SmartTicker']
def is_txid_sane(curs):
curs.execute("select txid_current()")
txid = curs.fetchone()[0]
# on 8.2 theres no such table
if not skytools.exists_table(curs, 'txid.epoch'):
return 1
curs.execute("select epoch, last_value from txid.epoch")
epoch, last_val = curs.fetchone()
stored_val = (epoch << 32) | last_val
if stored_val <= txid:
return 1
else:
return 0
class QueueStatus(object):
def __init__(self, name):
self.queue_name = name
self.seq_name = None
self.idle_period = 60
self.max_lag = 3
self.max_count = 200
self.last_tick_time = 0
self.last_count = 0
self.quiet_count = 0
def set_data(self, row):
self.seq_name = row['queue_event_seq']
self.idle_period = row['queue_ticker_idle_period']
self.max_lag = row['queue_ticker_max_lag']
self.max_count = row['queue_ticker_max_count']
def need_tick(self, cur_count, cur_time):
# check if tick is needed
need_tick = 0
lag = cur_time - self.last_tick_time
if cur_count == self.last_count:
# totally idle database
# don't go immidiately to big delays, as seq grows before commit
if self.quiet_count < 5:
if lag >= self.max_lag:
need_tick = 1
self.quiet_count += 1
else:
if lag >= self.idle_period:
need_tick = 1
else:
self.quiet_count = 0
# somewhat loaded machine
if cur_count - self.last_count >= self.max_count:
need_tick = 1
elif lag >= self.max_lag:
need_tick = 1
if need_tick:
self.last_tick_time = cur_time
self.last_count = cur_count
return need_tick
class SmartTicker(skytools.DBScript):
last_tick_event = 0
last_tick_time = 0
quiet_count = 0
tick_count = 0
maint_thread = None
def __init__(self, args):
skytools.DBScript.__init__(self, 'pgqadm', args)
self.ticker_log_time = 0
self.ticker_log_delay = 5*60
self.queue_map = {}
self.refresh_time = 0
def reload(self):
skytools.DBScript.reload(self)
self.ticker_log_delay = self.cf.getfloat("ticker_log_delay", 5*60)
def startup(self):
if self.maint_thread:
return
db = self.get_database("db", autocommit = 1)
cx = db.cursor()
ok = is_txid_sane(cx)
if not ok:
self.log.error('txid in bad state')
sys.exit(1)
self.maint_thread = MaintenanceJob(self, [self.cf.filename])
t = threading.Thread(name = 'maint_thread',
target = self.maint_thread.run)
t.setDaemon(1)
t.start()
def refresh_queues(self, cx):
q = "select queue_name, queue_event_seq,"\
" extract('epoch' from queue_ticker_idle_period) as queue_ticker_idle_period,"\
" extract('epoch' from queue_ticker_max_lag) as queue_ticker_max_lag,"\
" queue_ticker_max_count"\
" from pgq.queue"\
" where not queue_external_ticker"
cx.execute(q)
new_map = {}
data_list = []
for row in cx.dictfetchall():
queue_name = row['queue_name']
try:
que = self.queue_map[queue_name]
except KeyError, x:
que = QueueStatus(queue_name)
que.set_data(row)
new_map[queue_name] = que
p1 = "'%s', (select last_value from %s)" % (queue_name, que.seq_name)
data_list.append(p1)
self.queue_map = new_map
self.seq_query = "select %s" % (
", ".join(data_list))
if len(data_list) == 0:
self.seq_query = None
self.refresh_time = time.time()
def work(self):
db = self.get_database("db", autocommit = 1)
cx = db.cursor()
queue_refresh = self.cf.getint('queue_refresh_period', 30)
cur_time = time.time()
if cur_time >= self.refresh_time + queue_refresh:
self.refresh_queues(cx)
if not self.seq_query:
return
# now check seqs
cx.execute(self.seq_query)
res = cx.fetchone()
pos = 0
while pos < len(res):
id = res[pos]
val = res[pos + 1]
pos += 2
que = self.queue_map[id]
if que.need_tick(val, cur_time):
cx.execute("select pgq.ticker(%s)", [que.queue_name])
self.tick_count += 1
if cur_time > self.ticker_log_time + self.ticker_log_delay:
self.ticker_log_time = cur_time
self.stat_add('ticks', self.tick_count)
self.tick_count = 0
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