SQL Server 2008 Linked Server and ad-hoc INSERTs cause a rapid memory leak which eventually causes the server to become non-responsive and ends with the following error:
Msg 701, Level 17, State 123, Server BRECK-PC\SQLEXPRESS, Line 2
There is insufficient system memory in resource pool 'internal' to run this
query.
Location: qxcntxt.cpp:1052
Expression: cref == 0
SPID: 51
Process ID: 1880
The server remains non-responsive until SQL Server is restarted.
Software in use:
Windows Vista Ultimate 64 bit build 6001 SP1
Microsoft SQL Server 2008 (SP1) - 10.0.2734.0 (X64) Sep 11 2009 14:30:58 Copyright (c) 1988-2008 Microsoft Corporation Express Edition with Advanced Services (64-bit) on Windows NT 6.0 (Build 6001: Service Pack 1)
SAOLEDB.11 driver from SQL Anywhere 11.0.1.2276
Setting max server memory (MB) to 2048 did not help.
Adding various -g values (e.g., -g256;) to the server Startup Parameters did not help.
Using DBCC FREESYSTEMCACHE ( 'ALL' ), DBCC FREESESSIONCACHE and DBCC FREEPROCCACHE did not help.
Installing the Cumnulative update package 4 to SQL Server 2008 Service Pack 1 did not help, even though it contained a fix to a memory leak symptom involving Linked Server usage.
Separating the SELECT ... ROW_NUMBER() OVER ... query from the INSERT did not help. Experimentation showed that the complex SELECT did not cause the memory leak, the INSERT did.
Changing the code to use the ad-hoc "INSERT INTO OPENROWSET" syntax instead of a linked server did not help; the code below shows the linked server usage.
The sysinternals.com Process Explore utility shows that the memory usage was associated with sqlserver.exe, not the DLLs used by the SQL Anywhere OLEDB driver SAOLEDB.11.
Note that the SQL Anywhere version of linked server (proxy tables) works OK, to "pull" 1.9 million rows from a SQL Server 2008 table to a SQL Anywhere 11 database in a single transaction. The logic shown here is an attempt to use the linked server feature to "push" the rows; same direction, different syntax.
The code follows; 4G of RAM is exhausted after three or four executions of the EXECUTE copy_mss_t2:
EXEC sys.sp_configure
N'show advanced options',
N'1'
GO
RECONFIGURE WITH OVERRIDE
GO
EXEC sys.sp_configure
N'max server memory (MB)',
N'2048'
GO
RECONFIGURE WITH OVERRIDE
GO
EXEC sys.sp_configure
N'show advanced options',
N'0'
GO
RECONFIGURE WITH OVERRIDE
GO
EXEC master.dbo.sp_MSset_oledb_prop
N'SAOLEDB.11',
N'AllowInProcess',
1
GO
sp_addlinkedserver
@server = 'mem',
@srvproduct = 'SQL Anywhere OLE DB Provider',
@provider = 'SAOLEDB.11',
@datasrc = 'mem_PAVILION2'
GO
EXEC master.dbo.sp_serveroption
@server=N'mem',
@optname=N'rpc',
@optvalue=N'true'
GO
EXEC master.dbo.sp_serveroption
@server=N'mem',
@optname=N'rpc out',
@optvalue=N'true'
GO
sp_addlinkedsrvlogin
@rmtsrvname = 'mem',
@useself = 'false',
@locallogin = NULL,
@rmtuser = 'dba',
@rmtpassword = 'sql'
GO
CREATE PROCEDURE copy_mss_t2
@from_row BIGINT,
@to_row BIGINT,
@rows_copied_count BIGINT OUTPUT
AS
SELECT *
INTO #t
FROM ( SELECT *,
ROW_NUMBER()
OVER ( ORDER BY sample_set_number,
connection_number )
AS t2_row_number
FROM mss_t2 ) AS ordered_mss_t2
WHERE ordered_mss_t2.t2_row_number BETWEEN @from_row AND @to_row;
SELECT @rows_copied_count = COUNT(*)
FROM #t;
INSERT INTO mem..dba.sa_t2
SELECT sampling_id,
sample_set_number,
connection_number,
blocker_owner_table_name,
blocker_lock_type,
blocker_owner_name,
blocker_table_name,
blocker_reason,
blocker_row_identifier,
current_engine_version,
page_size,
ApproximateCPUTime,
BlockedOn,
BytesReceived,
BytesSent,
CacheHits,
CacheRead,
"Commit",
DiskRead,
DiskWrite,
FullCompare,
IndAdd,
IndLookup,
Isolation_level,
LastReqTime,
LastStatement,
LockCount,
LockName,
LockTableOID,
LoginTime,
LogWrite,
Name,
NodeAddress,
Prepares,
PrepStmt,
QueryLowMemoryStrategy,
QueryOptimized,
QueryReused,
ReqCountActive,
ReqCountBlockContention,
ReqCountBlockIO,
ReqCountBlockLock,
ReqCountUnscheduled,
ReqStatus,
ReqTimeActive,
ReqTimeBlockContention,
ReqTimeBlockIO,
ReqTimeBlockLock,
ReqTimeUnscheduled,
ReqType,
RequestsReceived,
Rlbk,
RollbackLogPages,
TempFilePages,
TransactionStartTime,
UncommitOp,
Userid,
previous_ApproximateCPUTime,
interval_ApproximateCPUTime,
previous_Commit,
interval_Commit,
previous_Rlbk,
interval_Rlbk
FROM #t;
GO
DECLARE @rows_copied_count BIGINT
EXECUTE copy_mss_t2 1110001, 1120000, @rows_copied_count OUTPUT
SELECT @rows_copied_count
GO
EXECUTE create_linked_server
GO
DECLARE @rows_copied_count BIGINT
EXECUTE copy_mss_t2 1120001, 1130000, @rows_copied_count OUTPUT
SELECT @rows_copied_count
GO
EXECUTE create_linked_server
GO
Here is the SQL Server source table, containing about 1G of data in 1.9 million rows:
CREATE TABLE mss_t2 (
sampling_id BIGINT NOT NULL,
sample_set_number BIGINT NOT NULL,
connection_number BIGINT NOT NULL,
blocker_owner_table_name VARCHAR ( 257 ) NULL,
blocker_lock_type VARCHAR ( 32 ) NULL,
blocker_owner_name VARCHAR ( 128 ) NULL,
blocker_table_name VARCHAR ( 128 ) NULL,
blocker_reason TEXT NULL,
blocker_row_identifier VARCHAR ( 32 ) NULL,
current_engine_version TEXT NOT NULL,
page_size INTEGER NOT NULL,
ApproximateCPUTime DECIMAL ( 30, 6 ) NULL,
BlockedOn BIGINT NULL,
BytesReceived BIGINT NULL,
BytesSent BIGINT NULL,
CacheHits BIGINT NULL,
CacheRead BIGINT NULL,
"Commit" BIGINT NULL,
DiskRead BIGINT NULL,
DiskWrite BIGINT NULL,
FullCompare BIGINT NULL,
IndAdd BIGINT NULL,
IndLookup BIGINT NULL,
Isolation_level BIGINT NULL,
LastReqTime TEXT NOT NULL DEFAULT '1900-01-01',
LastStatement TEXT NULL,
LockCount BIGINT NULL,
LockName BIGINT NULL,
LockTableOID BIGINT NULL,
LoginTime TEXT NOT NULL DEFAULT '1900-01-01',
LogWrite BIGINT NULL,
Name VARCHAR ( 128 ) NULL,
NodeAddress TEXT NULL,
Prepares BIGINT NULL,
PrepStmt BIGINT NULL,
QueryLowMemoryStrategy BIGINT NULL,
QueryOptimized BIGINT NULL,
QueryReused BIGINT NULL,
ReqCountActive BIGINT NULL,
ReqCountBlockContention BIGINT NULL,
ReqCountBlockIO BIGINT NULL,
ReqCountBlockLock BIGINT NULL,
ReqCountUnscheduled BIGINT NULL,
ReqStatus TEXT NULL,
ReqTimeActive DECIMAL ( 30, 6 ) NULL,
ReqTimeBlockContention DECIMAL ( 30, 6 ) NULL,
ReqTimeBlockIO DECIMAL ( 30, 6 ) NULL,
ReqTimeBlockLock DECIMAL ( 30, 6 ) NULL,
ReqTimeUnscheduled DECIMAL ( 30, 6 ) NULL,
ReqType TEXT NULL,
RequestsReceived BIGINT NULL,
Rlbk BIGINT NULL,
RollbackLogPages BIGINT NULL,
TempFilePages BIGINT NULL,
TransactionStartTime TEXT NOT NULL DEFAULT '1900-01-01',
UncommitOp BIGINT NULL,
Userid VARCHAR ( 128 ) NULL,
previous_ApproximateCPUTime DECIMAL ( 30, 6 ) NOT NULL DEFAULT 0.0,
interval_ApproximateCPUTime AS ( COALESCE ( "ApproximateCPUTime", 0 ) - previous_ApproximateCPUTime ),
previous_Commit BIGINT NOT NULL DEFAULT 0,
interval_Commit AS ( COALESCE ( "Commit", 0 ) - previous_Commit ),
previous_Rlbk BIGINT NOT NULL DEFAULT 0,
interval_Rlbk AS ( COALESCE ( Rlbk, 0 ) - previous_Rlbk ) )
Here is the target table in SQL Anywhere 11:
CREATE TABLE sa_t2 (
sampling_id BIGINT NOT NULL,
sample_set_number BIGINT NOT NULL,
connection_number BIGINT NOT NULL,
blocker_owner_table_name VARCHAR ( 257 ) NULL,
blocker_lock_type VARCHAR ( 32 ) NULL,
blocker_owner_name VARCHAR ( 128 ) NULL,
blocker_table_name VARCHAR ( 128 ) NULL,
blocker_reason TEXT NULL,
blocker_row_identifier VARCHAR ( 32 ) NULL,
current_engine_version TEXT NOT NULL,
page_size INTEGER NOT NULL,
ApproximateCPUTime DECIMAL ( 30, 6 ) NULL,
BlockedOn BIGINT NULL,
BytesReceived BIGINT NULL,
BytesSent BIGINT NULL,
CacheHits BIGINT NULL,
CacheRead BIGINT NULL,
"Commit" BIGINT NULL,
DiskRead BIGINT NULL,
DiskWrite BIGINT NULL,
FullCompare BIGINT NULL,
IndAdd BIGINT NULL,
IndLookup BIGINT NULL,
Isolation_level BIGINT NULL,
LastReqTime TEXT NOT NULL DEFAULT '1900-01-01',
LastStatement TEXT NULL,
LockCount BIGINT NULL,
LockName BIGINT NULL,
LockTableOID BIGINT NULL,
LoginTime TEXT NOT NULL DEFAULT '1900-01-01',
LogWrite BIGINT NULL,
Name VARCHAR ( 128 ) NULL,
NodeAddress TEXT NULL,
Prepares BIGINT NULL,
PrepStmt BIGINT NULL,
QueryLowMemoryStrategy BIGINT NULL,
QueryOptimized BIGINT NULL,
QueryReused BIGINT NULL,
ReqCountActive BIGINT NULL,
ReqCountBlockContention BIGINT NULL,
ReqCountBlockIO BIGINT NULL,
ReqCountBlockLock BIGINT NULL,
ReqCountUnscheduled BIGINT NULL,
ReqStatus TEXT NULL,
ReqTimeActive DECIMAL ( 30, 6 ) NULL,
ReqTimeBlockContention DECIMAL ( 30, 6 ) NULL,
ReqTimeBlockIO DECIMAL ( 30, 6 ) NULL,
ReqTimeBlockLock DECIMAL ( 30, 6 ) NULL,
ReqTimeUnscheduled DECIMAL ( 30, 6 ) NULL,
ReqType TEXT NULL,
RequestsReceived BIGINT NULL,
Rlbk BIGINT NULL,
RollbackLogPages BIGINT NULL,
TempFilePages BIGINT NULL,
TransactionStartTime TEXT NOT NULL DEFAULT '1900-01-01',
UncommitOp BIGINT NULL,
Userid VARCHAR ( 128 ) NULL,
previous_ApproximateCPUTime DECIMAL ( 30, 6 ) NOT NULL DEFAULT 0.0,
interval_ApproximateCPUTime DECIMAL ( 30, 6 ) NOT NULL COMPUTE ( COALESCE ( "ApproximateCPUTime", 0 ) - previous_ApproximateCPUTime ),
previous_Commit BIGINT NOT NULL DEFAULT 0,
interval_Commit BIGINT NOT NULL COMPUTE ( COALESCE ( "Commit", 0 ) - previous_Commit ),
previous_Rlbk BIGINT NOT NULL DEFAULT 0,
interval_Rlbk BIGINT NOT NULL COMPUTE ( COALESCE ( Rlbk, 0 ) - previous_Rlbk ),
PRIMARY KEY ( sample_set_number, connection_number ) );