File 0001-db-list-speedup.patch of Package openstack-neutron
From 0125cc8183b8835a28122aa5f6c28d8d7796f82e Mon Sep 17 00:00:00 2001
From: Dirk Mueller <dirk@dmllr.de>
Date: Fri, 9 Nov 2018 14:45:42 +0100
Subject: [PATCH] Newton Backport of:
https://review.openstack.org/#/c/567603/6
Improve DbListCommand operation from O(n^2) to O(n)
Right now the DbListCommand retrieves the uuid's of all the elements
passed in as argument. This is an O(n^2) operation so when the number
of elements in a grows it's likely that we get Timeout Exceptions.
Instead of doing this, whenever possible, we'll retrieve all the
elements (from the in-memory replica) and only fetch those who were
passed as arguments avoiding the O(n^2) operation.
NOTE: this cherry pick conflicted because in stable/pike, the commands.py
file was in different location.
Closes-Bug: #1769897
(cherry picked from fd64d41ea6f208a5752fbcd45952a04633ee1392)
Signed-off-by: Daniel Alvarez <dalvarez@redhat.com>
Change-Id: I69ea39a259d83cdd8512e77314d752de771f6ee5
---
neutron/agent/ovsdb/native/commands.py | 52 +++++++++++++++++---------
1 file changed, 34 insertions(+), 18 deletions(-)
diff --git a/neutron/agent/ovsdb/native/commands.py b/neutron/agent/ovsdb/native/commands.py
index deb4cdbfe7..3db5a47ebe 100644
--- a/neutron/agent/ovsdb/native/commands.py
+++ b/neutron/agent/ovsdb/native/commands.py
@@ -473,37 +473,53 @@ class DbListCommand(BaseCommand):
def run_idl(self, txn):
table_schema = self.api._tables[self.table]
+ idx = idlutils.get_index_column(table_schema)
columns = self.columns or list(table_schema.columns.keys()) + ['_uuid']
- if self.records:
- row_uuids = []
+ # If there's an index for this table, we'll fetch all columns and
+ # remove the unwanted ones based on self.records. Otherwise, let's try
+ # to get the uuid of the wanted ones which is an O(n^2) operation.
+ if not idx and self.records:
+ rows = []
for record in self.records:
try:
- row_uuids.append(idlutils.row_by_record(
- self.api.idl, self.table, record).uuid)
+ rows.append(idlutils.row_by_record(
+ self.api.idl, self.table, record))
except idlutils.RowNotFound:
if self.if_exists:
continue
- # NOTE(kevinbenton): this is converted to a RuntimeError
- # for compat with the vsctl version. It might make more
- # sense to change this to a RowNotFoundError in the future.
- raise RuntimeError(_(
- "Row doesn't exist in the DB. Request info: "
- "Table=%(table)s. Columns=%(columns)s. "
- "Records=%(records)s.") % {
- "table": self.table,
- "columns": self.columns,
- "records": self.records,
- })
+ self._raise_notfound()
else:
- row_uuids = table_schema.rows.keys()
+ rows = table_schema.rows.values()
+
+ if idx and self.records:
+ match = lambda row: getattr(row, idx) in self.records
+ else:
+ match = lambda row: True
+
self.result = [
{
- c: idlutils.get_column_value(table_schema.rows[uuid], c)
+ c: idlutils.get_column_value(row, c)
for c in columns
}
- for uuid in row_uuids
+ for row in rows if match(row)
]
+ if (not self.if_exists and idx and self.records and
+ len(self.result) < len(self.records)):
+ self._raise_notfound()
+
+ def _raise_notfound(self):
+ # NOTE(kevinbenton): this is converted to a RuntimeError
+ # for compat with the vsctl version. It might make more
+ # sense to change this to a RowNotFoundError in the future.
+ raise RuntimeError(
+ "Row doesn't exist in the DB. Request info: "
+ "Table=%(table)s. Columns=%(columns)s. "
+ "Records=%(records)s." % {
+ "table": self.table,
+ "columns": self.columns,
+ "records": self.records})
+
class DbFindCommand(BaseCommand):
def __init__(self, api, table, *conditions, **kwargs):
--
2.19.1
