/usr/lib/python3/dist-packages/londiste/playback.py is in python3-londiste 3.3.0-1.
This file is owned by root:root, with mode 0o644.
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from __future__ import division, absolute_import, print_function
import sys
import os
import time
import skytools
from pgq.cascade.worker import CascadedWorker
from londiste.handler import load_handler_modules, build_handler
from londiste.exec_attrs import ExecAttrs
__all__ = ['Replicator', 'TableState',
'TABLE_MISSING', 'TABLE_IN_COPY', 'TABLE_CATCHING_UP',
'TABLE_WANNA_SYNC', 'TABLE_DO_SYNC', 'TABLE_OK']
# state # owner - who is allowed to change
TABLE_MISSING = 0 # main
TABLE_IN_COPY = 1 # copy
TABLE_CATCHING_UP = 2 # copy
TABLE_WANNA_SYNC = 3 # main
TABLE_DO_SYNC = 4 # copy
TABLE_OK = 5 # setup
SYNC_OK = 0 # continue with batch
SYNC_LOOP = 1 # sleep, try again
SYNC_EXIT = 2 # nothing to do, exit script
MAX_PARALLEL_COPY = 8 # default number of allowed max parallel copy processes
class Counter(object):
"""Counts table statuses."""
missing = 0
copy = 0
catching_up = 0
wanna_sync = 0
do_sync = 0
ok = 0
def __init__(self, tables):
"""Counts and sanity checks."""
for t in tables:
if t.state == TABLE_MISSING:
self.missing += 1
elif t.state == TABLE_IN_COPY:
self.copy += 1
elif t.state == TABLE_CATCHING_UP:
self.catching_up += 1
elif t.state == TABLE_WANNA_SYNC:
self.wanna_sync += 1
elif t.state == TABLE_DO_SYNC:
self.do_sync += 1
elif t.state == TABLE_OK:
self.ok += 1
def get_copy_count(self):
return self.copy + self.catching_up + self.wanna_sync + self.do_sync
class TableState(object):
"""Keeps state about one table."""
def __init__(self, name, log):
"""Init TableState for one table."""
self.name = name
self.dest_table = name
self.log = log
# same as forget:
self.state = TABLE_MISSING
self.last_snapshot_tick = None
self.str_snapshot = None
self.from_snapshot = None
self.sync_tick_id = None
self.ok_batch_count = 0
self.last_tick = 0
self.table_attrs = {}
self.copy_role = None
self.dropped_ddl = None
self.plugin = None
# except this
self.changed = 0
# position in parallel copy work order
self.copy_pos = 0
# max number of parallel copy processes allowed
self.max_parallel_copy = MAX_PARALLEL_COPY
def forget(self):
"""Reset all info."""
self.state = TABLE_MISSING
self.last_snapshot_tick = None
self.str_snapshot = None
self.from_snapshot = None
self.sync_tick_id = None
self.ok_batch_count = 0
self.last_tick = 0
self.table_attrs = {}
self.changed = 1
self.plugin = None
self.copy_pos = 0
self.max_parallel_copy = MAX_PARALLEL_COPY
def change_snapshot(self, str_snapshot, tag_changed=1):
"""Set snapshot."""
if self.str_snapshot == str_snapshot:
return
self.log.debug("%s: change_snapshot to %s", self.name, str_snapshot)
self.str_snapshot = str_snapshot
if str_snapshot:
self.from_snapshot = skytools.Snapshot(str_snapshot)
else:
self.from_snapshot = None
if tag_changed:
self.ok_batch_count = 0
self.last_tick = None
self.changed = 1
def change_state(self, state, tick_id=None):
"""Set state."""
if self.state == state and self.sync_tick_id == tick_id:
return
self.state = state
self.sync_tick_id = tick_id
self.changed = 1
self.log.debug("%s: change_state to %s", self.name, self.render_state())
def render_state(self):
"""Make a string to be stored in db."""
if self.state == TABLE_MISSING:
return None
elif self.state == TABLE_IN_COPY:
return 'in-copy'
elif self.state == TABLE_CATCHING_UP:
return 'catching-up'
elif self.state == TABLE_WANNA_SYNC:
return 'wanna-sync:%d' % self.sync_tick_id
elif self.state == TABLE_DO_SYNC:
return 'do-sync:%d' % self.sync_tick_id
elif self.state == TABLE_OK:
return 'ok'
def parse_state(self, merge_state):
"""Read state from string."""
state = -1
if merge_state is None:
state = TABLE_MISSING
elif merge_state == "in-copy":
state = TABLE_IN_COPY
elif merge_state == "catching-up":
state = TABLE_CATCHING_UP
elif merge_state == "ok":
state = TABLE_OK
elif merge_state == "?":
state = TABLE_OK
else:
tmp = merge_state.split(':')
if len(tmp) == 2:
self.sync_tick_id = int(tmp[1])
if tmp[0] == 'wanna-sync':
state = TABLE_WANNA_SYNC
elif tmp[0] == 'do-sync':
state = TABLE_DO_SYNC
if state < 0:
raise Exception("Bad table state: %s" % merge_state)
return state
def loaded_state(self, row):
"""Update object with info from db."""
self.log.debug("loaded_state: %s: %s / %s",
self.name, row['merge_state'], row['custom_snapshot'])
self.change_snapshot(row['custom_snapshot'], 0)
self.state = self.parse_state(row['merge_state'])
self.changed = 0
if row['table_attrs']:
self.table_attrs = skytools.db_urldecode(row['table_attrs'])
else:
self.table_attrs = {}
self.copy_role = row['copy_role']
self.dropped_ddl = row['dropped_ddl']
if row['merge_state'] == "?":
self.changed = 1
self.copy_pos = int(row.get('copy_pos', '0'))
self.max_parallel_copy = int(self.table_attrs.get('max_parallel_copy',
self.max_parallel_copy))
if 'dest_table' in row and row['dest_table']:
self.dest_table = row['dest_table']
else:
self.dest_table = self.name
hstr = self.table_attrs.get('handlers', '') # compat
hstr = self.table_attrs.get('handler', hstr)
self.plugin = build_handler(self.name, hstr, self.dest_table)
def max_parallel_copies_reached(self):
return self.max_parallel_copy and\
self.copy_pos >= self.max_parallel_copy
def interesting(self, ev, tick_id, copy_thread, copy_table_name):
"""Check if table wants this event."""
if copy_thread:
if self.name != copy_table_name:
return False
if self.state not in (TABLE_CATCHING_UP, TABLE_DO_SYNC):
return False
else:
if self.state != TABLE_OK:
return False
# if no snapshot tracking, then accept always
if not self.from_snapshot:
return True
# uninteresting?
if self.from_snapshot.contains(ev.txid):
return False
# after couple interesting batches there no need to check snapshot
# as there can be only one partially interesting batch
if tick_id != self.last_tick:
self.last_tick = tick_id
self.ok_batch_count += 1
# disable batch tracking
if self.ok_batch_count > 3:
self.change_snapshot(None)
return True
def gc_snapshot(self, copy_thread, prev_tick, cur_tick, no_lag):
"""Remove attached snapshot if possible.
If the event processing is in current moment, the snapshot
is not needed beyond next batch.
The logic is needed for mostly unchanging tables,
where the .ok_batch_count check in .interesting()
method can take a lot of time.
"""
# check if gc is needed
if self.str_snapshot is None:
return
# check if allowed to modify
if copy_thread:
if self.state != TABLE_CATCHING_UP:
return
else:
if self.state != TABLE_OK:
return False
# aquire last tick
if not self.last_snapshot_tick:
if no_lag:
self.last_snapshot_tick = cur_tick
return
# reset snapshot if not needed anymore
if self.last_snapshot_tick < prev_tick:
self.change_snapshot(None)
def get_plugin(self):
return self.plugin
class Replicator(CascadedWorker):
"""Replication core.
Config options::
## Parameters for Londiste ##
# target database
db = dbname=somedb host=127.0.0.1
# extra connect string parameters to add to node public connect strings.
# useful values: user= sslmode=
#remote_extra_connstr =
# how many tables can be copied in parallel
#parallel_copies = 1
# accept only events for locally present tables
#local_only = true
## compare/repair
# max amount of time table can be locked
#lock_timeout = 10
# compare: sql to use
#compare_sql = select count(1) as cnt, sum(hashtext(t.*::text)) as chksum from only _TABLE_ t
# workaround for hashtext change between 8.3 and 8.4
#compare_sql = select count(1) as cnt, sum(('x' ||
# substr(md5(t.*::text),1,16))::bit(64)::bigint) as chksum from only _TABLE_ t
#compare_fmt = %(cnt)d rows, checksum=%(chksum)s
## Parameters for initial node creation: create-root/branch/leaf ##
# These parameters can be given on either command-line or in config
# command-line values override config values. Those values are
# used only during create time, otherwise they are loaded from database.
# Name for local node.
#node_name =
# public connect string for local node, which other nodes will use
# to connect to this one.
#public_node_location =
# connect string for existing node to use as provider
#initial_provider_location =
"""
# batch info
cur_tick = 0
prev_tick = 0
copy_table_name = None # filled by Copytable()
sql_list = []
current_event = None
def __init__(self, args):
"""Replication init."""
super(Replicator, self).__init__('londiste3', 'db', args)
self.table_list = []
self.table_map = {}
self.copy_thread = 0
self.set_name = self.queue_name
self.used_plugins = {}
self.parallel_copies = self.cf.getint('parallel_copies', 1)
if self.parallel_copies < 1:
raise Exception('Bad value for parallel_copies: %d' % self.parallel_copies)
self.consumer_filter = None
load_handler_modules(self.cf)
def connection_hook(self, dbname, db):
if dbname == 'db' and db.server_version >= 80300:
curs = db.cursor()
curs.execute("set session_replication_role = 'replica'")
db.commit()
code_check_done = 0
def check_code(self, db):
objs = [
skytools.DBFunction("pgq.maint_operations", 0, sql_file="londiste.maint-upgrade.sql"),
]
skytools.db_install(db.cursor(), objs, self.log)
db.commit()
def process_remote_batch(self, src_db, tick_id, ev_list, dst_db):
"All work for a batch. Entry point from SetConsumer."
self.current_event = None
# this part can play freely with transactions
if not self.code_check_done:
self.check_code(dst_db)
self.code_check_done = 1
self.sync_database_encodings(src_db, dst_db)
self.cur_tick = self.batch_info['tick_id']
self.prev_tick = self.batch_info['prev_tick_id']
dst_curs = dst_db.cursor()
self.load_table_state(dst_curs)
self.sync_tables(src_db, dst_db)
self.copy_snapshot_cleanup(dst_db)
# only main thread is allowed to restore fkeys
if not self.copy_thread:
self.restore_fkeys(dst_db)
for p in self.used_plugins.values():
p.reset()
self.used_plugins = {}
# now the actual event processing happens.
# they must be done all in one tx in dst side
# and the transaction must be kept open so that
# the cascade-consumer can save last tick and commit.
self.sql_list = []
super(Replicator, self).process_remote_batch(src_db, tick_id, ev_list, dst_db)
self.flush_sql(dst_curs)
for p in self.used_plugins.values():
p.finish_batch(self.batch_info, dst_curs)
self.used_plugins = {}
# finalize table changes
self.save_table_state(dst_curs)
# store event filter
if self.cf.getboolean('local_only', False):
# create list of tables
if self.copy_thread:
_filterlist = skytools.quote_literal(self.copy_table_name)
else:
_filterlist = ','.join(map(skytools.quote_literal, self.table_map.keys()))
# build filter
meta = "(ev_type like 'pgq.%' or ev_type like 'londiste.%')"
if _filterlist:
self.consumer_filter = "(%s or (ev_extra1 in (%s)))" % (meta, _filterlist)
else:
self.consumer_filter = meta
else:
# no filter
self.consumer_filter = None
def sync_tables(self, src_db, dst_db):
"""Table sync loop.
Calls appropriate handles, which is expected to
return one of SYNC_* constants."""
self.log.debug('Sync tables')
while 1:
cnt = Counter(self.table_list)
if self.copy_thread:
res = self.sync_from_copy_thread(cnt, src_db, dst_db)
else:
res = self.sync_from_main_thread(cnt, src_db, dst_db)
if res == SYNC_EXIT:
self.log.debug('Sync tables: exit')
if self.copy_thread:
self.unregister_consumer()
src_db.commit()
sys.exit(0)
elif res == SYNC_OK:
return
elif res != SYNC_LOOP:
raise Exception('Program error')
self.log.debug('Sync tables: sleeping')
time.sleep(3)
dst_db.commit()
self.load_table_state(dst_db.cursor())
dst_db.commit()
dsync_backup = None
def sync_from_main_thread(self, cnt, src_db, dst_db):
"Main thread sync logic."
# This operates on all table, any amount can be in any state
ret = SYNC_OK
if cnt.do_sync:
# wait for copy thread to catch up
ret = SYNC_LOOP
# we need to do wanna-sync->do_sync with small batches
need_dsync = False
dsync_ok = True
if self.pgq_min_interval or self.pgq_min_count:
dsync_ok = False
elif self.dsync_backup and self.dsync_backup[0] >= self.cur_tick:
dsync_ok = False
# now check if do-sync is needed
for t in self.get_tables_in_state(TABLE_WANNA_SYNC):
# copy thread wants sync, if not behind, do it
if self.cur_tick >= t.sync_tick_id:
if dsync_ok:
self.change_table_state(dst_db, t, TABLE_DO_SYNC, self.cur_tick)
ret = SYNC_LOOP
else:
need_dsync = True
# tune batch size if needed
if need_dsync:
if self.pgq_min_count or self.pgq_min_interval:
bak = (self.cur_tick, self.pgq_min_count, self.pgq_min_interval)
self.dsync_backup = bak
self.pgq_min_count = None
self.pgq_min_interval = None
elif self.dsync_backup:
self.pgq_min_count = self.dsync_backup[1]
self.pgq_min_interval = self.dsync_backup[2]
self.dsync_backup = None
# now handle new copies
npossible = self.parallel_copies - cnt.get_copy_count()
if cnt.missing and npossible > 0:
pmap = self.get_state_map(src_db.cursor())
src_db.commit()
for t in self.get_tables_in_state(TABLE_MISSING):
if 'copy_node' in t.table_attrs:
# should we go and check this node?
pass
else:
# regular provider is used
if t.name not in pmap:
self.log.warning("Table %s not available on provider", t.name)
continue
pt = pmap[t.name]
if pt.state != TABLE_OK: # or pt.custom_snapshot: # FIXME: does snapsnot matter?
self.log.info("Table %s not OK on provider, waiting", t.name)
continue
# don't allow more copies than configured
if npossible == 0:
break
npossible -= 1
# drop all foreign keys to and from this table
self.drop_fkeys(dst_db, t.dest_table)
# change state after fkeys are dropped thus allowing
# failure inbetween
self.change_table_state(dst_db, t, TABLE_IN_COPY)
# the copy _may_ happen immediately
self.launch_copy(t)
# there cannot be interesting events in current batch
# but maybe there's several tables, lets do them in one go
ret = SYNC_LOOP
return ret
def sync_from_copy_thread(self, cnt, src_db, dst_db):
"Copy thread sync logic."
# somebody may have done remove-table in the meantime
if self.copy_table_name not in self.table_map:
self.log.error("copy_sync: lost table: %s", self.copy_table_name)
return SYNC_EXIT
# This operates on single table
t = self.table_map[self.copy_table_name]
if t.state == TABLE_DO_SYNC:
# these settings may cause copy to miss right tick
self.pgq_min_count = None
self.pgq_min_interval = None
# main thread is waiting, catch up, then handle over
if self.cur_tick == t.sync_tick_id:
self.change_table_state(dst_db, t, TABLE_OK)
return SYNC_EXIT
elif self.cur_tick < t.sync_tick_id:
return SYNC_OK
else:
self.log.error("copy_sync: cur_tick=%d sync_tick=%d",
self.cur_tick, t.sync_tick_id)
raise Exception('Invalid table state')
elif t.state == TABLE_WANNA_SYNC:
# wait for main thread to react
return SYNC_LOOP
elif t.state == TABLE_CATCHING_UP:
# partition merging
if t.copy_role in ('wait-replay', 'lead'):
return SYNC_LOOP
# copy just finished
if t.dropped_ddl:
self.restore_copy_ddl(t, dst_db)
return SYNC_OK
# is there more work?
if self.work_state:
return SYNC_OK
# seems we have catched up
self.change_table_state(dst_db, t, TABLE_WANNA_SYNC, self.cur_tick)
return SYNC_LOOP
elif t.state == TABLE_IN_COPY:
# table is not copied yet, do it
self.do_copy(t, src_db, dst_db)
# forget previous value
self.work_state = 1
return SYNC_LOOP
else:
# nothing to do
return SYNC_EXIT
def restore_copy_ddl(self, ts, dst_db):
self.log.info("%s: restoring DDL", ts.name)
dst_curs = dst_db.cursor()
for ddl in skytools.parse_statements(ts.dropped_ddl):
self.log.info(ddl)
dst_curs.execute(ddl)
q = "select * from londiste.local_set_table_struct(%s, %s, NULL)"
self.exec_cmd(dst_curs, q, [self.queue_name, ts.name])
ts.dropped_ddl = None
dst_db.commit()
# analyze
self.log.info("%s: analyze", ts.name)
dst_curs.execute("analyze " + skytools.quote_fqident(ts.name))
dst_db.commit()
def do_copy(self, tbl, src_db, dst_db):
"""Callback for actual copy implementation."""
raise Exception('do_copy not implemented')
def process_remote_event(self, src_curs, dst_curs, ev):
"""handle one event"""
self.log.debug("New event: id=%s / type=%s / data=%s / extra1=%s", ev.id, ev.type, ev.data, ev.extra1)
# set current_event only if processing them one-by-one
if self.work_state < 0:
self.current_event = ev
if ev.type in ('I', 'U', 'D'):
self.handle_data_event(ev, dst_curs)
elif ev.type[:2] in ('I:', 'U:', 'D:'):
self.handle_data_event(ev, dst_curs)
elif ev.type == "R":
self.flush_sql(dst_curs)
self.handle_truncate_event(ev, dst_curs)
elif ev.type == 'EXECUTE':
self.flush_sql(dst_curs)
self.handle_execute_event(ev, dst_curs)
elif ev.type == 'londiste.add-table':
self.flush_sql(dst_curs)
self.add_set_table(dst_curs, ev.data)
elif ev.type == 'londiste.remove-table':
self.flush_sql(dst_curs)
self.remove_set_table(dst_curs, ev.data)
elif ev.type == 'londiste.remove-seq':
self.flush_sql(dst_curs)
self.remove_set_seq(dst_curs, ev.data)
elif ev.type == 'londiste.update-seq':
self.flush_sql(dst_curs)
self.update_seq(dst_curs, ev)
else:
super(Replicator, self).process_remote_event(src_curs, dst_curs, ev)
# no point keeping it around longer
self.current_event = None
def handle_data_event(self, ev, dst_curs):
"""handle one data event"""
t = self.get_table_by_name(ev.extra1)
if not t or not t.interesting(ev, self.cur_tick, self.copy_thread, self.copy_table_name):
self.stat_increase('ignored_events')
return
try:
p = self.used_plugins[ev.extra1]
except KeyError:
p = t.get_plugin()
self.used_plugins[ev.extra1] = p
p.prepare_batch(self.batch_info, dst_curs)
p.process_event(ev, self.apply_sql, dst_curs)
def handle_truncate_event(self, ev, dst_curs):
"""handle one truncate event"""
t = self.get_table_by_name(ev.extra1)
if not t or not t.interesting(ev, self.cur_tick, self.copy_thread, self.copy_table_name):
self.stat_increase('ignored_events')
return
fqname = skytools.quote_fqident(t.dest_table)
try:
p = self.used_plugins[ev.extra1]
except KeyError:
p = t.get_plugin()
self.used_plugins[ev.extra1] = p
if p.conf.get('ignore_truncate'):
self.log.info("ignoring truncate for %s", fqname)
return
#
# Always use CASCADE, because without it the
# operation cannot work with FKeys, on both
# slave and master.
#
sql = "TRUNCATE %s CASCADE;" % fqname
self.flush_sql(dst_curs)
dst_curs.execute(sql)
def handle_execute_event(self, ev, dst_curs):
"""handle one EXECUTE event"""
if self.copy_thread:
return
# parse event
fname = ev.extra1
s_attrs = ev.extra2
exec_attrs = ExecAttrs(urlenc=s_attrs)
sql = ev.data
# fixme: curs?
pgver = dst_curs.connection.server_version
if pgver >= 80300:
dst_curs.execute("set local session_replication_role = 'local'")
seq_map = {}
q = "select seq_name, local from londiste.get_seq_list(%s) where local"
dst_curs.execute(q, [self.queue_name])
for row in dst_curs.fetchall():
seq_map[row['seq_name']] = row['seq_name']
tbl_map = {}
for t in self.table_map.values():
tbl_map[t.name] = t.dest_table
q = "select * from londiste.execute_start(%s, %s, %s, false, %s)"
res = self.exec_cmd(dst_curs, q, [self.queue_name, fname, sql, s_attrs], commit=False)
ret = res[0]['ret_code']
if ret > 200:
self.log.warning("Skipping execution of '%s'", fname)
if pgver >= 80300:
dst_curs.execute("set local session_replication_role = 'replica'")
return
if exec_attrs.need_execute(dst_curs, tbl_map, seq_map):
self.log.info("%s: executing sql")
xsql = exec_attrs.process_sql(sql, tbl_map, seq_map)
for stmt in skytools.parse_statements(xsql):
dst_curs.execute(stmt)
else:
self.log.info("%s: execution not needed on this node")
q = "select * from londiste.execute_finish(%s, %s)"
self.exec_cmd(dst_curs, q, [self.queue_name, fname], commit=False)
if pgver >= 80300:
dst_curs.execute("set local session_replication_role = 'replica'")
def apply_sql(self, sql, dst_curs):
# how many queries to batch together, drop batching on error
limit = 200
if self.work_state == -1:
limit = 0
self.sql_list.append(sql)
if len(self.sql_list) >= limit:
self.flush_sql(dst_curs)
def flush_sql(self, dst_curs):
"""Send all buffered statements to DB."""
if len(self.sql_list) == 0:
return
buf = "\n".join(self.sql_list)
self.sql_list = []
dst_curs.execute(buf)
def add_set_table(self, dst_curs, tbl):
"""There was new table added to root, remember it."""
q = "select londiste.global_add_table(%s, %s)"
dst_curs.execute(q, [self.set_name, tbl])
def remove_set_table(self, dst_curs, tbl):
"""There was table dropped from root, remember it."""
if tbl in self.table_map:
t = self.table_map[tbl]
del self.table_map[tbl]
self.table_list.remove(t)
q = "select londiste.global_remove_table(%s, %s)"
dst_curs.execute(q, [self.set_name, tbl])
def remove_set_seq(self, dst_curs, seq):
"""There was seq dropped from root, remember it."""
q = "select londiste.global_remove_seq(%s, %s)"
dst_curs.execute(q, [self.set_name, seq])
def load_table_state(self, curs):
"""Load table state from database.
Todo: if all tables are OK, there is no need
to load state on every batch.
"""
q = "select * from londiste.get_table_list(%s)"
curs.execute(q, [self.set_name])
new_list = []
new_map = {}
for row in curs.fetchall():
if not row['local']:
continue
t = self.get_table_by_name(row['table_name'])
if not t:
t = TableState(row['table_name'], self.log)
t.loaded_state(row)
new_list.append(t)
new_map[t.name] = t
self.table_list = new_list
self.table_map = new_map
def get_state_map(self, curs):
"""Get dict of table states."""
q = "select * from londiste.get_table_list(%s)"
curs.execute(q, [self.set_name])
new_map = {}
for row in curs.fetchall():
if not row['local']:
continue
t = TableState(row['table_name'], self.log)
t.loaded_state(row)
new_map[t.name] = t
return new_map
def save_table_state(self, curs):
"""Store changed table state in database."""
for t in self.table_list:
# backwards compat: move plugin-only dest_table to table_info
if t.dest_table != t.plugin.dest_table:
self.log.info("Overwriting .dest_table from plugin: tbl=%s dst=%s",
t.name, t.plugin.dest_table)
q = "update londiste.table_info set dest_table = %s"\
" where queue_name = %s and table_name = %s"
curs.execute(q, [t.plugin.dest_table, self.set_name, t.name])
if not t.changed:
continue
merge_state = t.render_state()
self.log.info("storing state of %s: copy:%d new_state:%s",
t.name, self.copy_thread, merge_state)
q = "select londiste.local_set_table_state(%s, %s, %s, %s)"
curs.execute(q, [self.set_name,
t.name, t.str_snapshot, merge_state])
t.changed = 0
def change_table_state(self, dst_db, tbl, state, tick_id=None):
"""Chage state for table."""
tbl.change_state(state, tick_id)
self.save_table_state(dst_db.cursor())
dst_db.commit()
self.log.info("Table %s status changed to '%s'", tbl.name, tbl.render_state())
def get_tables_in_state(self, state):
"get all tables with specific state"
for t in self.table_list:
if t.state == state:
yield t
def get_table_by_name(self, name):
"""Returns cached state object."""
if name.find('.') < 0:
name = "public.%s" % name
if name in self.table_map:
return self.table_map[name]
return None
def launch_copy(self, tbl_stat):
"""Run parallel worker for copy."""
self.log.info("Launching copy process")
main_exe = sys.argv[0]
conf = self.cf.filename
cmd = [main_exe, conf, 'copy', tbl_stat.name, '-d']
# pass same verbosity options as main script got
if self.options.quiet:
cmd.append('-q')
if self.options.verbose:
cmd += ['-v'] * self.options.verbose
# let existing copy finish and clean its pidfile,
# otherwise new copy will exit immediately.
# FIXME: should not happen on per-table pidfile ???
copy_pidfile = "%s.copy.%s" % (self.pidfile, tbl_stat.name)
while skytools.signal_pidfile(copy_pidfile, 0):
self.log.warning("Waiting for existing copy to exit")
time.sleep(2)
# launch and wait for daemonization result
self.log.debug("Launch args: %r", cmd)
res = os.spawnvp(os.P_WAIT, main_exe, cmd)
self.log.debug("Launch result: %r", res)
if res != 0:
self.log.error("Failed to launch copy process, result=%d", res)
def sync_database_encodings(self, src_db, dst_db):
"""Make sure client_encoding is same on both side."""
try:
# psycopg2
if src_db.encoding != dst_db.encoding:
dst_db.set_client_encoding(src_db.encoding)
except AttributeError:
# psycopg1
src_curs = src_db.cursor()
dst_curs = dst_db.cursor()
src_curs.execute("show client_encoding")
src_enc = src_curs.fetchone()[0]
dst_curs.execute("show client_encoding")
dst_enc = dst_curs.fetchone()[0]
if src_enc != dst_enc:
dst_curs.execute("set client_encoding = %s", [src_enc])
def copy_snapshot_cleanup(self, dst_db):
"""Remove unnecessary snapshot info from tables."""
no_lag = not self.work_state
changes = False
for t in self.table_list:
t.gc_snapshot(self.copy_thread, self.prev_tick, self.cur_tick, no_lag)
if t.changed:
changes = True
if changes:
self.save_table_state(dst_db.cursor())
dst_db.commit()
def restore_fkeys(self, dst_db):
"""Restore fkeys that have both tables on sync."""
dst_curs = dst_db.cursor()
# restore fkeys -- one at a time
q = "select * from londiste.get_valid_pending_fkeys(%s)"
dst_curs.execute(q, [self.set_name])
fkey_list = dst_curs.fetchall()
for row in fkey_list:
self.log.info('Creating fkey: %(fkey_name)s (%(from_table)s --> %(to_table)s)', row)
q2 = "select londiste.restore_table_fkey(%(from_table)s, %(fkey_name)s)"
dst_curs.execute(q2, row)
dst_db.commit()
def drop_fkeys(self, dst_db, table_name):
"""Drop all foreign keys to and from this table.
They need to be dropped one at a time to avoid deadlocks with user code.
"""
dst_curs = dst_db.cursor()
q = "select * from londiste.find_table_fkeys(%s)"
dst_curs.execute(q, [table_name])
fkey_list = dst_curs.fetchall()
for row in fkey_list:
self.log.info('Dropping fkey: %s', row['fkey_name'])
q2 = "select londiste.drop_table_fkey(%(from_table)s, %(fkey_name)s)"
dst_curs.execute(q2, row)
dst_db.commit()
def process_root_node(self, dst_db):
"""On root node send seq changes to queue."""
super(Replicator, self).process_root_node(dst_db)
q = "select * from londiste.root_check_seqs(%s)"
self.exec_cmd(dst_db, q, [self.queue_name])
def update_seq(self, dst_curs, ev):
if self.copy_thread:
return
val = int(ev.data)
seq = ev.extra1
q = "select * from londiste.global_update_seq(%s, %s, %s)"
self.exec_cmd(dst_curs, q, [self.queue_name, seq, val])
def copy_event(self, dst_curs, ev, filtered_copy):
# send only data events down (skipping seqs also)
if filtered_copy:
if ev.type[:9] in ('londiste.',):
return
super(Replicator, self).copy_event(dst_curs, ev, filtered_copy)
def exception_hook(self, det, emsg):
# add event info to error message
if self.current_event:
ev = self.current_event
info = "[ev_id=%d,ev_txid=%d] " % (ev.ev_id, ev.ev_txid)
emsg = info + emsg
super(Replicator, self).exception_hook(det, emsg)
if __name__ == '__main__':
script = Replicator(sys.argv[1:])
script.start()
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