| Bug #953 | memory leak calling libmysql and dep. lib. (ODBC , ADO) | ||
|---|---|---|---|
| Submitted: | 30 Jul 2003 5:06 | Modified: | 4 Aug 2003 18:39 |
| Reporter: | khoa do | Email Updates: | |
| Status: | Can't repeat | Impact on me: | |
| Category: | MySQL Server | Severity: | S1 (Critical) |
| Version: | 4.0.13-nt | OS: | Windows (Windows 2000) |
| Assigned to: | MySQL Verification Team | CPU Architecture: | Any |
[30 Jul 2003 5:06]
khoa do
sql scripts
Attachment: dbrule.zip (application/x-zip-compressed, text), 3.20 KiB.
[30 Jul 2003 5:11]
khoa do
rulecom com component, ADO component data layer
Attachment: rulecom.zip (application/x-zip-compressed, text), 105.75 KiB.
[30 Jul 2003 5:11]
khoa do
test client for rulecom component
Attachment: testrulecom.zip (application/x-zip-compressed, text), 3.98 KiB.
[30 Jul 2003 5:12]
khoa do
ODBC client
Attachment: dbupdate1.zip (application/x-zip-compressed, text), 5.67 KiB.
[30 Jul 2003 5:14]
khoa do
libmysqltest test client with slight modifications
Attachment: libmysqltest.zip (application/x-zip-compressed, text), 22.75 KiB.
[30 Jul 2003 5:44]
khoa do
All projects files opened and save with VS.NET 2003.
[30 Jul 2003 9:07]
MySQL Verification Team
The *zip files uploaded I got them corrupted. Could you please download them again at: ftp://support.mysql.com:/pub/mysql/secret
[30 Jul 2003 12:15]
khoa do
At Miguel Solorzano request, I have uploaded the files to ftp://support.mysql.com:/pub/mysql/secret
[4 Aug 2003 6:39]
MySQL Verification Team
Thank you, now I was able for to get the files and begin the tests.
[4 Aug 2003 10:31]
MySQL Verification Team
Could you please verify if the below support article can be applied in your Win2k machine: 280790 - Memory Manager Allocates Paged Pool Before it Is Needed http://support.microsoft.com/?kbid=280790
[4 Aug 2003 11:29]
khoa do
Yes, the fix http://support.microsoft.com/?kbid=280790 is on the server. The server has service pack 3 which contains the hotfix. However, I will apply service pack 4 to check. Please stand by.
[4 Aug 2003 15:03]
khoa do
I have applied servicepack 4 which should have all the latest hotfixes and including the one described earlier and I am still getting the memory leak. :-(
[4 Aug 2003 18:39]
MySQL Verification Team
For practical reasons I began to test for a while your third case reported:
*******************************************************************************
3. Native+libmysql and C - noticed great increased memory usage, great increase in page faults in clients that made repeated "select" calls - I thought that using native calls would fix my memory leak issue but it turned out that I may have been experiencing the memory leak right in the libmysql client library
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I modified your code of MyTest for to match the connection with my environment, performed two tests with the MySQL dynamic and static libraries.
Create a Purify session and create a Performance log with the Windows System
Performance Monitor with the below counters:
Memory -> Available bytes
Process -> Handle Count, Pool nonpaged bytes, pool paged bytes and private
bytes.
At the end of my test, Purify has reported:
[I] Summary of all memory leaks... {0 bytes, 0 blocks}
[I] Summary of new memory leaks... {0 bytes, 0 blocks}
[I] Program terminated at 04/08/2003 21:51:26
and the counters's behavior on the Performance Monitor are confirmed
the result I got from Purify.
So I am assuming that some environment issues (hardware, applications
installed, code of your application, etc) are the cause of your problem.
Description: I have had memory leaks calling libmysql and other dependent libraries. As a result, my COM and ASP applications which are dependent on a MySQL backend do not function properly after a few days because increased memory usage crashes the ASP runtime engine. How to repeat: dbrule.zip (SQL scripts for the db) 1. ADO+MySQL ODBC driver 3.51 and C++ - noticed increased memory usage, handle counts, great increase in page faults in clients that made repeated "select" calls - when I switched to MSSQL OLEDB and Oracle ODBC drivers the memory usage, handle counts, and page faults stabilized. ex. rulecom.zip (com component), testrulecom.zip (test client) 2. ODBC+MySQL ODBC driver 3.51 and C++ - noticed increased memory usage, great increase in page faults in clients that made repeated "select" calls ex. dbupdate1.zip (ODBC test client) 3. Native+libmysql and C - noticed great increased memory usage, great increase in page faults in clients that made repeated "select" calls - I thought that using native calls would fix my memory leak issue but it turned out that I may have been experiencing the memory leak right in the libmysql client library ex. libmysqltest.zip (a slight modification of libmysqltest to make repeated calls) Suggested fix: I have looked at the source for libmysql and without looking too much further and without understanding the architecture I have made the following observations: 1. "free_old_query" cannot properly free "mysql->field_alloc" because "mysql->fields == NULL" while "unpack_fields" seems to be responsible for the memory allocation. Again, I don't understand enough of the architecture to understand what this means.