AppDomain was unloaded - out of memory happened

Question

Hi,
Please help me to resolve this SQL server error - Im getting below error occasionally and sometimes it gets resolved
by itself.
Error:
AppDomain mydatabase.public[runtime].44 was unloaded by escalation policy to ensure the consistency of your application. Out of memory happened while accessing a critical resource. 
System.Threading.ThreadAbortException: Thread was being aborted. System.Threading.ThreadAbortException:     at System.Data.SqlClient.SqlConnection..ctor(String connectionString)    at MsSqlSpatial.DatabaseHelper.get_Connection()   
at TableValuedFunctions.SpatialQuery.Execute(SqlString table_name, SqlString column_name, SqlBytes ewkbMBR, SqlBytes ewkb, SqlString condition, Arguments args, ReaderHandler handler)    at TableValuedFunctions.FilterQuery(SqlString table_name,
SqlString column_name, SqlBytes ewkb)
Server version: SQL Server 2008 R2 SP1 standard  edition - 32 bit
OS: SQL Server 2003 enterprice SP2
Please guide me how to resolve this.
Thank you
Sathish

Answer 1

Hello,
First upgrade your SQL Server to SP2 ASAP.
This cannot be necessarily a issue.If you see this message few times in errorlog you can ignore it.If this message comes very frequently it can be issue.But in your case since you got OOM error .Its seems CLR hit VAS limitation.
Now First thing I would ask are you using CLR .You can check CLR enabled value in sp_configure.In 32 bit system CLR takes memory otside form buffer pool and since VAS region is limited to 2 G( unless you use /3 G switch) this can cause issue.
Permanent solution to this is migrating your server to 64 bit to make VAS 8 TB.Temporary solution would be to look at queries fetching data sets using CLR.Datasets utilizes heavy memory.
Unfortunately I have not worked on CLR.
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