Commit 4500b04a authored by Boxiang Sun's avatar Boxiang Sun Committed by Vincent Pelletier

CMFActivity: Use a random value for activity uids

Sequential number generators stored in a fixed-size format eventually run
out of values. But activity queues only care about what activities are
currently present: any uid can be reused as soon as it is available.
So stop using a sequential id generator for activity uids, and instead use
random values.

Vincent Pelletier:
- Commit message.
- Minor formatting changes.
- Do probability computations, and increase activity uid storage size to
  64bits integers, up from 32.
- Apply to SQLJobLib too.
parent a001329f
......@@ -28,6 +28,9 @@
import sys
import transaction
from random import getrandbits
import MySQLdb
from MySQLdb.constants.ER import DUP_ENTRY
from DateTime import DateTime
from Shared.DC.ZRDB.Results import Results
from Shared.DC.ZRDB.DA import DatabaseError
......@@ -47,6 +50,19 @@ READ_MESSAGE_LIMIT = 1000
# TODO: Limit by size in bytes instead of number of rows.
MAX_MESSAGE_LIST_SIZE = 100
INVOKE_ERROR_STATE = -2
# Activity uids are stored as 64 bits unsigned integers.
# No need to depend on a database that supports unsigned integers.
# Numbers are far big enough without using the MSb. Assuming a busy activity
# table having one million activities, the probability of triggering a conflict
# when inserting one activity with 64 bits uid is 0.5e-13. With 63 bits it
# increases to 1e-13, which is still very low.
UID_SAFE_BITSIZE = 63
# Inserting an activity batch of 100 activities among one million existing
# activities has a probability of failing of 1e-11. While it should be low
# enough, retries can help lower that. Try 10 times, which should be short
# enough while yielding one order of magnitude collision probability
# improvement.
UID_ALLOCATION_TRY_COUNT = 10
def sort_message_key(message):
# same sort key as in SQLBase.getMessageList
......@@ -126,8 +142,6 @@ class SQLBase(Queue):
portal = activity_tool.getPortalObject()
for i in xrange(0, len(registered_message_list), MAX_MESSAGE_LIST_SIZE):
message_list = registered_message_list[i:i+MAX_MESSAGE_LIST_SIZE]
uid_list = portal.portal_ids.generateNewIdList(self.uid_group,
id_count=len(message_list), id_generator='uid')
path_list = ['/'.join(m.object_path) for m in message_list]
active_process_uid_list = [m.active_process_uid for m in message_list]
method_id_list = [m.method_id for m in message_list]
......@@ -141,9 +155,14 @@ class SQLBase(Queue):
for m in message_list:
m.order_validation_text = x = self.getOrderValidationText(m)
processing_node_list.append(0 if x == 'none' else -1)
for _ in xrange(UID_ALLOCATION_TRY_COUNT):
try:
portal.SQLBase_writeMessageList(
table=self.sql_table,
uid_list=uid_list,
uid_list=[
getrandbits(UID_SAFE_BITSIZE)
for _ in xrange(len(message_list))
],
path_list=path_list,
active_process_uid_list=active_process_uid_list,
method_id_list=method_id_list,
......@@ -154,6 +173,13 @@ class SQLBase(Queue):
tag_list=tag_list,
processing_node_list=processing_node_list,
serialization_tag_list=serialization_tag_list)
except MySQLdb.IntegrityError, (code, _):
if code != DUP_ENTRY:
raise
else:
break
else:
raise ValueError("Maximum retry for SQLBase_writeMessageList reached")
def getNow(self, context):
"""
......
......@@ -26,10 +26,15 @@
#
##############################################################################
from random import getrandbits
from zLOG import LOG, TRACE, INFO, WARNING, ERROR, PANIC
from SQLBase import SQLBase, sort_message_key, MAX_MESSAGE_LIST_SIZE
import MySQLdb
from MySQLdb.constants.ER import DUP_ENTRY
from SQLBase import (
SQLBase, sort_message_key, MAX_MESSAGE_LIST_SIZE,
UID_SAFE_BITSIZE, UID_ALLOCATION_TRY_COUNT,
)
from Products.CMFActivity.ActivityTool import Message
from SQLDict import SQLDict
class SQLJoblib(SQLDict):
......@@ -69,8 +74,6 @@ class SQLJoblib(SQLDict):
portal = activity_tool.getPortalObject()
for i in xrange(0, len(registered_message_list), MAX_MESSAGE_LIST_SIZE):
message_list = registered_message_list[i:i+MAX_MESSAGE_LIST_SIZE]
uid_list = portal.portal_ids.generateNewIdList(self.uid_group,
id_count=len(message_list), id_generator='uid')
path_list = ['/'.join(m.object_path) for m in message_list]
active_process_uid_list = [m.active_process_uid for m in message_list]
method_id_list = [m.method_id for m in message_list]
......@@ -85,8 +88,13 @@ class SQLJoblib(SQLDict):
for m in message_list:
m.order_validation_text = x = self.getOrderValidationText(m)
processing_node_list.append(0 if x == 'none' else -1)
for _ in xrange(UID_ALLOCATION_TRY_COUNT):
try:
portal.SQLJoblib_writeMessage(
uid_list=uid_list,
uid_list=[
getrandbits(UID_SAFE_BITSIZE)
for _ in xrange(len(message_list))
],
path_list=path_list,
active_process_uid_list=active_process_uid_list,
method_id_list=method_id_list,
......@@ -98,6 +106,13 @@ class SQLJoblib(SQLDict):
processing_node_list=processing_node_list,
signature_list=signature_list,
serialization_tag_list=serialization_tag_list)
except MySQLdb.IntegrityError, (code, _):
if code != DUP_ENTRY:
raise
else:
break
else:
raise ValueError("Maximum retry for SQLBase_writeMessageList reached")
def getProcessableMessageLoader(self, activity_tool, processing_node):
path_and_method_id_dict = {}
......
......@@ -9,7 +9,7 @@ class_file:
</dtml-comment>
<params>table</params>
CREATE TABLE <dtml-var table> (
`uid` INT UNSIGNED NOT NULL,
`uid` BIGINT UNSIGNED NOT NULL,
`date` DATETIME NOT NULL,
`path` VARCHAR(255) NOT NULL,
`active_process_uid` INT UNSIGNED NULL,
......
......@@ -9,7 +9,7 @@ class_file:
</dtml-comment>
<params></params>
CREATE TABLE message_job (
`uid` INT UNSIGNED NOT NULL,
`uid` BIGINT UNSIGNED NOT NULL,
`date` DATETIME NOT NULL,
`path` VARCHAR(255) NOT NULL,
`active_process_uid` INT UNSIGNED NULL,
......
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