rda.SubmitSql cause outofmemoryexception

My application create quite a lot log file to submit to the server under WiFi coverage to monitor the application. (log is just txt file). as time goes on, submitsql method throw OutOfMemoryException. I agree my log file is quite big, 80K each and 6 log files to submit.
My log submitter is an instance object. I also tried static object but it doesn't help either.

I do dispose my rda object when it is out.

Is any way I can fix this?Could you provide som sample code - I do not understand the connection between the log files and submitsql - are you submitting the log file text in an insert statement?|||

Sure.

public LogSubmitter()

{

//some local objects.

public void SubmitLog(string logName, SqlCeRemoteDataAccess rda)

{

try

{

//

//read text from log file and append it to StringBuilder: logBuilder

//

string logCmd = "EXEC InsertLog "+"'"+logBuilder.ToString()+"'";

rda.SubmitSql(logCmd ,remoteConnStr);

}

catch(Exception ex)

{

Log.WriteException(ex);

}

}

}

where, InsertLog is a stored procedure on the server.

Is there is problem with this code?

PS: I only submit log when device is under WiFi coverage. rda object is disposed in the caller.

|||Have a close look at your StringBuilder - have you set a useful initial capacity - otherwise you should try that.|||

Thank you very much.

You are right, I didn't set initial capacity. Another reason could be I submit 6 log files continously, each log about takes 80k (max).

But one thing I cannot understand is that I called logBuilder.Remove(0,logBuilder) before submitting each log, so each stringbuilder should be empty before appending new log.

|||Did we solve your outofmemory exeption problems, then?|||

Just got log from my test scanner.

It still has this exception. I will do more changes with "capacity" property.

By the way, does StringBuilder has maximum capacity?

Cheers

|||It does, but the MacCapacity property is not available in NETCF, (according to docs) so who knows what it may be?|||

Thanks Erik.

Is StringBuilder's memory reused if we remove contents from it and then append string again?

|||

Yes, ErikJ, I resolved this issue by checking the length before appending new chars.

The StringBuilder throws "OutofMemoryException" when it's length is greater than 2359294.

Thanks.

|||

Hi, ErikEJ;

Now I have this exception again. The "Length" property is 57341 when this happens.

And I call "Remove" method after I finish submitting a log. It looks like GC doesn't collect those memory.

Thanks.

rda.SubmitSql cause outofmemoryexception

My application create quite a lot log file to submit to the server under WiFi coverage to monitor the application. (log is just txt file). as time goes on, submitsql method throw OutOfMemoryException. I agree my log file is quite big, 80K each and 6 log files to submit.
My log submitter is an instance object. I also tried static object but it doesn't help either.

I do dispose my rda object when it is out.

Is any way I can fix this?Could you provide som sample code - I do not understand the connection between the log files and submitsql - are you submitting the log file text in an insert statement?|||

Sure.

public LogSubmitter()

{

//some local objects.

public void SubmitLog(string logName, SqlCeRemoteDataAccess rda)

{

try

{

//

//read text from log file and append it to StringBuilder: logBuilder

//

string logCmd = "EXEC InsertLog "+"'"+logBuilder.ToString()+"'";

rda.SubmitSql(logCmd ,remoteConnStr);

}

catch(Exception ex)

{

Log.WriteException(ex);

}

}

}

where, InsertLog is a stored procedure on the server.

Is there is problem with this code?

PS: I only submit log when device is under WiFi coverage. rda object is disposed in the caller.

|||Have a close look at your StringBuilder - have you set a useful initial capacity - otherwise you should try that.|||

Thank you very much.

You are right, I didn't set initial capacity. Another reason could be I submit 6 log files continously, each log about takes 80k (max).

But one thing I cannot understand is that I called logBuilder.Remove(0,logBuilder) before submitting each log, so each stringbuilder should be empty before appending new log.

|||Did we solve your outofmemory exeption problems, then?|||

Just got log from my test scanner.

It still has this exception. I will do more changes with "capacity" property.

By the way, does StringBuilder has maximum capacity?

Cheers

|||It does, but the MacCapacity property is not available in NETCF, (according to docs) so who knows what it may be?|||

Thanks Erik.

Is StringBuilder's memory reused if we remove contents from it and then append string again?

|||

Yes, ErikJ, I resolved this issue by checking the length before appending new chars.

The StringBuilder throws "OutofMemoryException" when it's length is greater than 2359294.

Thanks.

|||

Hi, ErikEJ;

Now I have this exception again. The "Length" property is 57341 when this happens.

And I call "Remove" method after I finish submitting a log. It looks like GC doesn't collect those memory.

Thanks.

rda.SubmitSql cause outofmemoryexception

My application create quite a lot log file to submit to the server under WiFi coverage to monitor the application. (log is just txt file). as time goes on, submitsql method throw OutOfMemoryException. I agree my log file is quite big, 80K each and 6 log files to submit.
My log submitter is an instance object. I also tried static object but it doesn't help either.

I do dispose my rda object when it is out.

Is any way I can fix this?Could you provide som sample code - I do not understand the connection between the log files and submitsql - are you submitting the log file text in an insert statement?|||

Sure.

public LogSubmitter()

{

//some local objects.

public void SubmitLog(string logName, SqlCeRemoteDataAccess rda)

{

try

{

//

//read text from log file and append it to StringBuilder: logBuilder

//

string logCmd = "EXEC InsertLog "+"'"+logBuilder.ToString()+"'";

rda.SubmitSql(logCmd ,remoteConnStr);

}

catch(Exception ex)

{

Log.WriteException(ex);

}

}

}

where, InsertLog is a stored procedure on the server.

Is there is problem with this code?

PS: I only submit log when device is under WiFi coverage. rda object is disposed in the caller.

|||Have a close look at your StringBuilder - have you set a useful initial capacity - otherwise you should try that.|||

Thank you very much.

You are right, I didn't set initial capacity. Another reason could be I submit 6 log files continously, each log about takes 80k (max).

But one thing I cannot understand is that I called logBuilder.Remove(0,logBuilder) before submitting each log, so each stringbuilder should be empty before appending new log.

|||Did we solve your outofmemory exeption problems, then?|||

Just got log from my test scanner.

It still has this exception. I will do more changes with "capacity" property.

By the way, does StringBuilder has maximum capacity?

Cheers

|||It does, but the MacCapacity property is not available in NETCF, (according to docs) so who knows what it may be?|||

Thanks Erik.

Is StringBuilder's memory reused if we remove contents from it and then append string again?

|||

Yes, ErikJ, I resolved this issue by checking the length before appending new chars.

The StringBuilder throws "OutofMemoryException" when it's length is greater than 2359294.

Thanks.

|||

Hi, ErikEJ;

Now I have this exception again. The "Length" property is 57341 when this happens.

And I call "Remove" method after I finish submitting a log. It looks like GC doesn't collect those memory.

Thanks.

rda.SubmitSql cause outofmemoryexception

My application create quite a lot log file to submit to the server under WiFi coverage to monitor the application. (log is just txt file). as time goes on, submitsql method throw OutOfMemoryException. I agree my log file is quite big, 80K each and 6 log files to submit.
My log submitter is an instance object. I also tried static object but it doesn't help either.

I do dispose my rda object when it is out.

Is any way I can fix this?Could you provide som sample code - I do not understand the connection between the log files and submitsql - are you submitting the log file text in an insert statement?|||

Sure.

public LogSubmitter()

{

//some local objects.

public void SubmitLog(string logName, SqlCeRemoteDataAccess rda)

{

try

{

//

//read text from log file and append it to StringBuilder: logBuilder

//

string logCmd = "EXEC InsertLog "+"'"+logBuilder.ToString()+"'";

rda.SubmitSql(logCmd ,remoteConnStr);

}

catch(Exception ex)

{

Log.WriteException(ex);

}

}

}

where, InsertLog is a stored procedure on the server.

Is there is problem with this code?

PS: I only submit log when device is under WiFi coverage. rda object is disposed in the caller.

|||Have a close look at your StringBuilder - have you set a useful initial capacity - otherwise you should try that.|||

Thank you very much.

You are right, I didn't set initial capacity. Another reason could be I submit 6 log files continously, each log about takes 80k (max).

But one thing I cannot understand is that I called logBuilder.Remove(0,logBuilder) before submitting each log, so each stringbuilder should be empty before appending new log.

|||Did we solve your outofmemory exeption problems, then?|||

Just got log from my test scanner.

It still has this exception. I will do more changes with "capacity" property.

By the way, does StringBuilder has maximum capacity?

Cheers

|||It does, but the MacCapacity property is not available in NETCF, (according to docs) so who knows what it may be?|||

Thanks Erik.

Is StringBuilder's memory reused if we remove contents from it and then append string again?

|||

Yes, ErikJ, I resolved this issue by checking the length before appending new chars.

The StringBuilder throws "OutofMemoryException" when it's length is greater than 2359294.

Thanks.

|||

Hi, ErikEJ;

Now I have this exception again. The "Length" property is 57341 when this happens.

And I call "Remove" method after I finish submitting a log. It looks like GC doesn't collect those memory.

Thanks.

rda.SubmitSql cause outofmemoryexception

My application create quite a lot log file to submit to the server under WiFi coverage to monitor the application. (log is just txt file). as time goes on, submitsql method throw OutOfMemoryException. I agree my log file is quite big, 80K each and 6 log files to submit.
My log submitter is an instance object. I also tried static object but it doesn't help either.

I do dispose my rda object when it is out.

Is any way I can fix this?Could you provide som sample code - I do not understand the connection between the log files and submitsql - are you submitting the log file text in an insert statement?|||

Sure.

public LogSubmitter()

{

//some local objects.

public void SubmitLog(string logName, SqlCeRemoteDataAccess rda)

{

try

{

//

//read text from log file and append it to StringBuilder: logBuilder

//

string logCmd = "EXEC InsertLog "+"'"+logBuilder.ToString()+"'";

rda.SubmitSql(logCmd ,remoteConnStr);

}

catch(Exception ex)

{

Log.WriteException(ex);

}

}

}

where, InsertLog is a stored procedure on the server.

Is there is problem with this code?

PS: I only submit log when device is under WiFi coverage. rda object is disposed in the caller.

|||Have a close look at your StringBuilder - have you set a useful initial capacity - otherwise you should try that.|||

Thank you very much.

You are right, I didn't set initial capacity. Another reason could be I submit 6 log files continously, each log about takes 80k (max).

But one thing I cannot understand is that I called logBuilder.Remove(0,logBuilder) before submitting each log, so each stringbuilder should be empty before appending new log.

|||Did we solve your outofmemory exeption problems, then?|||

Just got log from my test scanner.

It still has this exception. I will do more changes with "capacity" property.

By the way, does StringBuilder has maximum capacity?

Cheers

|||It does, but the MacCapacity property is not available in NETCF, (according to docs) so who knows what it may be?|||

Thanks Erik.

Is StringBuilder's memory reused if we remove contents from it and then append string again?

|||

Yes, ErikJ, I resolved this issue by checking the length before appending new chars.

The StringBuilder throws "OutofMemoryException" when it's length is greater than 2359294.

Thanks.

|||

Hi, ErikEJ;

Now I have this exception again. The "Length" property is 57341 when this happens.

And I call "Remove" method after I finish submitting a log. It looks like GC doesn't collect those memory.

Thanks.

RDA with Identity column.

Hi Everyone:

I am new to Mobile programming. I am now working on a mobile project. I encounter an issue when I sync the data:

cause I can't modify the schema, so I have to use RDA instead of Merge replication on sql server 2005.

However, There is an identiy column on each table I will pull them down to local mobile database. And I will use those identity columns to connect tables. Even worse, the photo's new name will combine the photoID which is an identity column. There would an issue, if i sync data, the photoID would be same on different local mobile databases. And there would be generate same identity value when users sync data.

How can I avoid those issues? If you have any good ideas, please help me out so that I can meet the project deadline.

Thanks

James

Anyone knows how to manually handle identity management.

Cause my identity column will clash when Sync data.

James

|||

You need to call

ALTER TABLE <TableName> ALTER COLUMN <ColumnName> <ColumnDataType> IDENTITY(<Seed>,<Step>)

to set the different identity on the pulled table.

Note, only Seed and Step can be changed in the above table.

Thanks,

Laxmi Narsimha Rao ORUGANTI

|||

Hi Laxmi,

Thank you for your reply. I realize that I can use the command you gave to change the SEED range to avoid the clash. But if I change seed, when I push the data back to Remote SQL server 2005 database, should I disable the identity column on remote database, then push mobile client table data, then set identity column back on remote DB. It seems lots of work to manually handle identity column clash. Do we have any alternative way to do it, since I can't use merge replication to change the database schema, what about XML web service? I think should be same, but if we use Web Service, the performance should be down 10-15%, that's why i don't wanna use it since we choose SQL server 2005 as our database.

Your reply is really appreciated. Thanks!

James

|||

I need to point is that someone will work on remote db through classical ASP. If I change the identity Seed. It will effect mobile client?

If anybody has the same issues?

Thanks

James

|||

No need to worry about disabling the IDENTITY on server. RDA while pushing automatically does "SET IDENTITY_INSERT <TableName> ON/OFF" on SQL Server to get the same IDENTITY column values onto the server table.

Thanks,

Laxmi

|||

Thank Laxmi,

your reply does help me. I will try it out. But we have 200 hundred of Mobile clients. We have to set the identity range for each one.

Any other good ideas for solving the identity clash.

Thanks.

James

|||That is why there is Merge Replication! Why not go for that?|||

Because I can't modify the Sql server 2005 DB schema. They are using identity ID. I wish I could use Merge replication. I can save my code lines as well.

Thank you . Laxmi. You are the rock!

James

|||Same here, merge replication is not a option.

Anyone found a suitable solution for this challenge?

Thanx
|||What I have done is to set the ID range for each person. So that they won't clash.

Rapid deletes cause a deadlock

Hello all.

Please help me shed light on the following problem:

I am deleting from 2 tables in a transaction. I experience a deadlock occasionally when deleting.
Here are the tables:

create table TABLE_1 (
ID integer not null,
TYPE_CD varchar(50) not null,
STATUS_ID integer not null,
NAME varchar(500) not null,
COMMENT varchar(500) null,
CREATED_DATE datetime not null,
CREATED_BY varchar(15) not null,
LASTMOD_DATE datetime null,
LASTMOD_BY varchar(15) null,
constraint PK_TABLE_1 primary key nonclustered (ID)
)

create table TABLE_2 (
TASK_ID integer not null,
TABLE_1_ID integer not null,
COMMENT varchar(500) null,
constraint PK_TABLE_2 primary key nonclustered (TASK_ID, TABLE_1_ID)
)

Table table_2 is an intersection table between table_1 and another lookup table (called task).
Whenever I delete from table_1 I need to delete from table_2 to maintain integrity.
The reason I do not have clustered indexes on the tables is b/c they start out empty (every day a housekeeping task deletes from them. Unfortunately I cannot change this...).

In my (web/jsp) application before I delete, I select from table_1 to get data I need to remember after the delete.
In order to avoid the "select for update problem", I use the "UPDLOCK" hint in the select like this:

select *
from table_1 WITH (UPDLOCK),
table_2 WITH (UPDLOCK)
where table_1.id = table_2.table_1_id "
and table_1.id = ?
and table_2.task_id = ?

I then issue my deletes in the following order:

delete from table_1
where task_id = ?
and table_1_id = ?

and then,

delete from table_1 where id = ?

The application sets the isolation level to READ COMMITTED.
The above 3 sql statements are executed as part of a transaction. Occasionally, when I drive the application, I get a deadlock. This happens intermittently. I have been able to reproduce the problem by attempting to delete records really fast, one after the other from the (web) front end.
When the deadlock occurs these are the locks that are held by the running processes:

Blocked SPID (10):
============

Object Lock Type Mode Status Owner Index Resource
app DB S GRANT Sess TABLE_2
app.dbo.TABLE_1 TAB IX GRANT Xact TABLE_2
app.dbo.TABLE_1 KEY U GRANT Xact PK_TABLE_2 (a400f609034c)
app.dbo.TABLE_1 RID U GRANT Xact TABLE_2 1:157:3
app.dbo.TABLE_1 PAG IU GRANT Xact PK_TABLE_2 1:443
app.dbo.TABLE_1 PAG IU GRANT Xact TABLE_2 1:157
app.dbo.TABLE_2 KEY S WAIT Xact PK_TABLE_2 (6501eda29ac1)
app.dbo.TABLE_2 KEY S GRANT Xact PK_TABLE_2 (ef007b1066ea)
app.dbo.TABLE_2 TAB IS GRANT Xact TABLE_2
app.dbo.TABLE_2 PAG IS GRANT Xact PK_TABLE_2 1:252

Blocking SPID (12):
=============
Object Lock Type Mode Status Owner Index Resource
app DB S GRANT Sess TABLE_2
app.dbo.TABLE_2 KEY X GRANT Xact PK_TABLE_2 (6501eda29ac1)
app.dbo.TABLE_2 RID X GRANT Xact TABLE_2 1:176:3
app.dbo.TABLE_2 TAB IX GRANT Xact TABLE_2
app.dbo.TABLE_2 PAG IX GRANT Xact PK_TABLE_2 1:252
app.dbo.TABLE_2 PAG IX GRANT Xact TABLE_2 1:176

I could not figure out what the problem is. Please help me with this.
Any help will be much appreciated.

Thanks in advanceThat transaction isolation level is probably not sufficient. I don't think that "WITH(UPDLOCK)" is going to hold beyond the completion of that query.

If the request is to delete from two tables in turn, you need to be sure that you have free-and-clear access to both of them before you begin. And I think you're going to have to do that on the transaction level, with an isolation greater than READ COMMITTED. Otherwise, as you're seeing, "sporadically" the computer is able to finish its work on the first table, only to discover a conflicting lock on the second.

Obviously if the problem happens enough to be a noticeable 'problem' you may need to re-think your approach: there is obviously a lot of contention on that second table.

As I see it, "READ COMMITTED" implies that you are reading, not that you are writing. And you're not only writing, you're deleting ... Intrusive though it may be, I think you're going to have to use higher levels.|||Thank you for your response. I'll set the isolation level to REPEATABLE READ for the transaction and re-test. (Thinking about it a bit more I think your suggestion will solve my problem :) I'll post again to let you know my test results.

Best regards!