My application is using AppFabric for our distributed caching model in a production web farm of windows web 5 servers. The application is a .net4 c# web application. We are encountering some problems with AppFabric and have some questions regarding the setup of such. The main issue we have is if one of the web 5 servers is restarted, the site on the other servers will also go down for a short period of time with appfabric exceptions like the following appearing in our event logs:
Message: ErrorCode:SubStatus:There is a temporary failure. Please retry later.
ErrorCode:SubStatus:Region referred to does not exist. Use CreateRegion API to fix the error.
We have a cache provider wrapper class that creates the datacachefactory object etc and is used as the intermediatory between the web application and appfabric. This is a singleton class so only one instance of the datacachefactory object is created on the Init of the class.
The second error above I believe I have found the reason for, in our code the region was being created on the Init ie at the very start, but if a node comes out of the cluster that contains the region in its memorary, then the above error is a result. To resolve this issue, the region should be attempted to be created on every request appfabric - but only creating it if it does not exist - does this sound correct?
Regarding the other error, I believe it may be down to the configruation. This is the cluster config xml file:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="dataCache" type="Microsoft.ApplicationServer.Caching.DataCacheSection, Microsoft.ApplicationServer.Caching.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</configSections>
<dataCache size="Small">
<caches>
<cache consistency="StrongConsistency" name="App1Cache"
secondaries="1">
<policy>
<eviction type="Lru" />
<expiration defaultTTL="10" isExpirable="true" />
</policy>
</cache>
<cache consistency="StrongConsistency" name="App2Cache"
secondaries="1">
<policy>
<eviction type="Lru" />
<expiration defaultTTL="10" isExpirable="true" />
</policy>
</cache>
<cache consistency="StrongConsistency" name="App3Cache"
secondaries="1">
<policy>
<eviction type="Lru" />
<expiration defaultTTL="10" isExpirable="true" />
</policy>
</cache>
<cache consistency="StrongConsistency" name="default">
<policy>
<eviction type="Lru" />
<expiration defaultTTL="10" isExpirable="true" />
</policy>
</cache>
</caches>
<hosts>
<host replicationPort="22236" arbitrationPort="22235" clusterPort="22234"
hostId="724664608" size="1228" leadHost="true" account="SERVER1\user"
cacheHostName="AppFabricCachingService" name="SERVER1"
cachePort="22233" />
<host replicationPort="22236" arbitrationPort="22235" clusterPort="22234"
hostId="598646137" size="1228" leadHost="true" account="SERVER2\user"
cacheHostName="AppFabricCachingService" name="SERVER2"
cachePort="22233" />
<host replicationPort="22236" arbitrationPort="22235" clusterPort="22234"
hostId="358039700" size="1228" leadHost="true" account="SERVER3\user"
cacheHostName="AppFabricCachingService" name="SERVER3"
cachePort="22233" />
<host replicationPort="22236" arbitrationPort="22235" clusterPort="22234"
hostId="929915039" size="1228" leadHost="false" account="SERVER4\user"
cacheHostName="AppFabricCachingService" name="SERVER4"
cachePort="22233" />
<host replicationPort="22236" arbitrationPort="22235" clusterPort="22234"
hostId="1752630351" size="1228" leadHost="false" account="SERVER5\user"
cacheHostName="AppFabricCachingService" name="SERVER5"
cachePort="22233" />
</hosts>
<advancedProperties>
<securityProperties>
<authorization>
<allow users="everyone" />
</authorization>
</securityProperties>
</advancedProperties>
</dataCache>
</configuration>
Note: we have multiple we caches set up as we have multiple applications using appfabric, and seeing same issues with them all.
And this is the web.config entry in the application on each of the servers:
<dataCacheClient requestTimeout="15000" channelOpenTimeout="3000" maxConnectionsToServer="1">
<localCache isEnabled="true" sync="TimeoutBased" ttlValue="300" objectCount="10000" />
<clientNotification pollInterval="300" maxQueueLength="10000" />
<hosts>
<host name="SERVER1" cachePort="22233" />
<host name="SERVER2" cachePort="22233" />
<host name="SERVER3" cachePort="22233" />
<host name="SERVER4" cachePort="22233" />
<host name="SERVER5" cachePort="22233" />
</hosts>
<transportProperties connectionBufferSize="131072" maxBufferPoolSize="268435456" maxBufferSize="8388608" maxOutputDelay="2" channelInitializationTimeout="60000" receiveTimeout="600000" /></dataCacheClient>
Anyone see a problem with the above? As you can see we have 3 lead hosts and 2 secondaries.
Some questions I have following on from this are:
I have read about having a local cache - what is the technical benefit of this? ie. will this give a local copy of the data per node.
What is the best practice regarding ports? Are the above ports correct or could there be conflicts with the same ports being used?
The 3 lead hosts and 2 secondaries, is this a recommended split? Does it mean there are 3 copies of the data?
When we are restarting the servers, we attempt to never restart the lead hosts at the same time.
Thanks for any feedback on this!
We make extensive use of AppFabric caching. You are going to see the
Message: ErrorCode:SubStatus:There is a temporary failure. Please retry later.
fairly often. It's probably best to write yourself a wrapper around AppFabric that automates retries when this error is thrown. You really want to use exponential backoff, but failing that randomizing the retry period may be enough.
The cache configuration in the Web.config file is only used to create the cache factory. It will contact one of the hosts and obtain the cluster configuration from that. The only benefit to listing all hosts in your Web.config is so that if a host is down it can contact another host. Even if you only listed a single host, provided that was present your caching would work fine.
Using a local cache is likely to improve performance if you read objects more frequently than you write them. You're going to have to tune the size of that by experimentation.
Related
I'm struggling to get my IIS site to autostart. I'm using Quartz.Net inside it for nightly tasks but they aren't running because IIS disposes of it before they can run. I've attempted to set it to autostart and stay runninig by doing the following (using these instructions):
ApplicationHost.Config:
<configuration>
<configSections>
...
<system.applicationHost>
<applicationPools>
<add name="DefaultAppPool" enable32BitAppOnWin64="true" managedRuntimeVersion="v4.0" />
<add name="ASP.NET v4.0" enable32BitAppOnWin64="false" managedRuntimeVersion="v4.0" />
<add name="ASP.NET v4.0 Classic" managedRuntimeVersion="v4.0" managedPipelineMode="Classic" />
<add name="Classic .NET AppPool" managedRuntimeVersion="v4.0" managedPipelineMode="Classic" />
...
<add name="AUTOSTARTSITE" autoStart="true" managedPipelineMode="Integrated" startMode="AlwaysRunning">
<processModel identityType="NetworkService" />
</add>
<applicationPoolDefaults managedRuntimeVersion="v4.0">
<processModel identityType="NetworkService" />
</applicationPoolDefaults>
</applicationPools>
...
<sites>
<site name="AUTOSTARTSITE" id="10" serverAutoStart="true" serviceAutoStartEnabled="true" serviceAutoStartProvider="StartUpCode">
<application path="/" applicationPool="AUTOSTARTSITE">
<virtualDirectory path="/" physicalPath="E:\websites\AUTOSTARTSITE" />
</application>
<bindings>
<binding protocol="http" bindingInformation="*:80:AUTOSTARTSITE.com" />
</bindings>
<traceFailedRequestsLogging enabled="true" />
<logFile directory="%SystemDrive%\inetpub\logs\LogFiles" />
</site>
<siteDefaults>
<logFile logFormat="W3C" directory="%SystemDrive%\inetpub\logs\LogFiles" />
<traceFailedRequestsLogging directory="%SystemDrive%\inetpub\logs\FailedReqLogFiles" />
</siteDefaults>
<applicationDefaults applicationPool="DefaultAppPool" />
<virtualDirectoryDefaults allowSubDirConfig="true" />
</sites>
<serviceAutoStartProviders>
<add name="StartUpCode" type="StartUpCode, AUTOSTARTSITE" />
</serviceAutoStartProviders>
<webLimits />
</system.applicationHost>
...
And here is my startup code. I didn't put in a namespace, and I have it log that it runs so I can confirm the process is working. Unfortunatly, it does not run.
StartUpCode:
public class StartUpCode : System.Web.Hosting.IProcessHostPreloadClient
{
readonly log4net.ILog logger = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
public void Preload(string[] parameters)
{
SetupJobs();
logger.Info("Quartz Jobs Setup Successfully");
}
}
Despite these changes, it runs the same as before. Am I missing something obvious?
I think for all this stuff to work properly you need to install Application Initialization feature for IIS:
You can find more details on how it is supposed to work here.
We found generally that no matter what sometimes it just does not work. So there are really 2 solutions here:
Do not run scheduler in IIS, use Windows Service or scheduled task maybe
Write a pinger that will again be either windows service or scheduled task. It's probably one line with powershell to issue a GET to your site. That can run again as a service or scheduled task.
I would definitely prefer option 1 to not depend on IIS life-cycle for critical scheduling operations. Even though this approach with IIS hosting is still quite popular and we use it there is just too many problems with it in my experience.
We too had same issue using Quartz the reason was the IIS pool was shutting down after some idle time.So we had to prevent it from shutting down and it worked for Us.
Find more details here
I've been having an issue on an Umbraco 7.5.6 site hosted in an App Service on Azure where the indexes seem to be dropped after an unspecific amount of time.
We're storing information, including some custom fields, on published news articles in the External Examine index to query stories from the index. This is consumed by our client-facing search API.
Initially, we thought that this might be caused by Azure swapping servers so removed the {computerName} parameter from the path under ExamineSettings.config. However, that didn't appear to have any effect.
Our current index path is ~/App_Data/TEMP/ExamineIndexes/External/
The ExamineSettings.config file is as follows:
<Examine>
<ExamineIndexProviders>
<providers>
<add name="InternalIndexer" type="UmbracoExamine.UmbracoContentIndexer, UmbracoExamine"
supportUnpublished="true"
supportProtected="true"
analyzer="Lucene.Net.Analysis.WhitespaceAnalyzer, Lucene.Net"/>
<add name="InternalMemberIndexer" type="UmbracoExamine.UmbracoMemberIndexer, UmbracoExamine"
supportUnpublished="true"
supportProtected="true"
analyzer="Lucene.Net.Analysis.Standard.StandardAnalyzer, Lucene.Net"/>
<!-- default external indexer, which excludes protected and unpublished pages-->
<add name="ExternalIndexer" type="UmbracoExamine.UmbracoContentIndexer, UmbracoExamine"/>
</providers>
</ExamineIndexProviders>
<ExamineSearchProviders defaultProvider="ExternalSearcher">
<providers>
<add name="InternalSearcher" type="UmbracoExamine.UmbracoExamineSearcher, UmbracoExamine"
analyzer="Lucene.Net.Analysis.WhitespaceAnalyzer, Lucene.Net"/>
<add name="ExternalSearcher" type="UmbracoExamine.UmbracoExamineSearcher, UmbracoExamine" />
<add name="InternalMemberSearcher" type="UmbracoExamine.UmbracoExamineSearcher, UmbracoExamine"
analyzer="Lucene.Net.Analysis.Standard.StandardAnalyzer, Lucene.Net" enableLeadingWildcard="true"/>
</providers>
</ExamineSearchProviders>
</Examine>
Due to the unpredictable nature of this issue, short of writing a WebJob to republish the articles on a regular basis, I'm unsure of what to try next.
First thing to do is update your examine config
The filesystem attached to web apps is actually a UNC share which can suffer from IO latency issues which in turn can cause Umbraco to flip out a little bit.
Try updating your ExamineSettings.config as per the following and add this to the indexer(s):
directoryFactory="Examine.LuceneEngine.Directories.SyncTempEnvDirectoryFactory,Examine"
The SyncTempEnvDirectoryFactory enables Examine to sync indexes
between the remote file system and the local environment temporary
storage directory, the indexes will be accessed from the temporary
storage directory. This setting is required due to the nature of
Lucene files and IO latency on Azure Web Apps.
This should take performance issues out of the equation.
Then, debugging
Indexing issues should be picked up in Umbraco's logs (some at Info level, some at Debug). If you're not already capturing Umbraco's logs then use something like Papertrail or Application Insights to collect the logs and see if you can identify what's causing the deletion (you may need to drop logging level to Debug to catch it).
N.B if you do push logs to an external service then wrap it in the Async/Parallel provider from Umbraco Core: here's an example config.
<log4net>
<root>
<priority value="Info"/>
<appender-ref ref="AsynchronousLog4NetAppender" />
</root>
<appender name="AsynchronousLog4NetAppender" type="Umbraco.Core.Logging.ParallelForwardingAppender,Umbraco.Core">
<appender-ref ref="PapertrailRemoteSyslogAppender"/>
</appender>
<appender name="PapertrailRemoteSyslogAppender" type="log4net.Appender.RemoteSyslogAppender">
<facility value="Local6" />
<identity value="%date{yyyy-MM-ddTHH:mm:ss.ffffffzzz} your-site-name %P{log4net:HostName}" />
<layout type="log4net.Layout.PatternLayout" value="%level - %message%newline" />
<remoteAddress value="logsN.papertrailapp.com" />
<remotePort value="XXXXX" />
</appender>
<!--Here you can change the way logging works for certain namespaces -->
<logger name="NHibernate">
<level value="WARN" />
</logger>
</log4net>
I'm performing a migration of database, SQL Server to Oracle, in a C# application. The application mentioned, is using Entity Framework to access the database.
In this database there's a procedure that returns a "ComplexType", I researched and found that Oracle does not understand the "ComplexType" and I need to perform the mapping of the output parameter in web.config, then:
<oracle.manageddataaccess.client>
<version number="*">
<implicitRefCursor>
<storedProcedure schema="ALERTA_MPLUS" name="PR_CONSULTA_DADOS_ROBO">
<refCursor name="CV_1">
<bindInfo mode="Output" />
<metadata columnOrdinal="0" columnName="Broker" baseColumnName="Broker" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="Varchar2" providerType="Varchar2" columnSize="50" />
<metadata columnOrdinal="1" columnName="Companhia" baseColumnName="Companhia" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="Varchar2" providerType="Varchar2" columnSize="100" />
<metadata columnOrdinal="2" columnName="Metrica" baseColumnName="Metrica" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="Varchar2" providerType="Varchar2" columnSize="50" />
<metadata columnOrdinal="3" columnName="Q1" baseColumnName="Q1" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="NVarchar2" providerType="NVarchar2" columnSize="50" />
<metadata columnOrdinal="4" columnName="Q2" baseColumnName="Q2" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="NVarchar2" providerType="NVarchar2" columnSize="50" />
<metadata columnOrdinal="5" columnName="Q3" baseColumnName="Q3" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="NVarchar2" providerType="NVarchar2" columnSize="50" />
<metadata columnOrdinal="6" columnName="Q4" baseColumnName="Q4" baseSchemaName="ALERTA_MPLUS" baseTableName="tt_Resultado_Final" nativeDataType="NVarchar2" providerType="NVarchar2" columnSize="50" />
</refCursor>
</storedProcedure>
</implicitRefCursor>
</version>
</oracle.manageddataaccess.client>
This mapping worked perfectly in the development environment, but when I passed the application for approval gave the following error:
I've tried some solutions but none was successful:
ODAC installed on the server approval;
Searching, I found the Oracle documentation that indicates the mapping that way:
<oracle.dataaccess.client>
<settings>
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursor.CV_1" value="implicitRefCursor bindinfo='mode=Output'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.0" value="implicitRefCursor metadata='ColumnName=Broker;BaseColumnName=Broker;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=Varchar2;ProviderType=Varchar2'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.1" value="implicitRefCursor metadata='ColumnName=Companhia;BaseColumnName=Companhia;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=Varchar2;ProviderType=Varchar2'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.2" value="implicitRefCursor metadata='ColumnName=Metrica;BaseColumnName=Metrica;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=Varchar2;ProviderType=Varchar2'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.3" value="implicitRefCursor metadata='ColumnName=Q1;BaseColumnName=Q1;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=NVarchar2;ProviderType=NVarchar2'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.4" value="implicitRefCursor metadata='ColumnName=Q2;BaseColumnName=Q2;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=NVarchar2;ProviderType=NVarchar2'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.5" value="implicitRefCursor metadata='ColumnName=Q3;BaseColumnName=Q3;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=NVarchar2;ProviderType=NVarchar2'" />
<add name="ALERTA_MPLUS.PR_CONSULTA_DADOS_ROBO.RefCursorMetaData.CV_1.Column.6" value="implicitRefCursor metadata='ColumnName=Q4;BaseColumnName=Q4;BaseSchemaName=ALERTA_MPLUS;BaseTableName=tt_Resultado_Final;NATIVEDATATYPE=NVarchar2;ProviderType=NVarchar2'" />
</settings>
</oracle.dataaccess.client>
This is code return the following error (in all environments):
ORA-06550: line 1, colunm 8: PLS-00306:
wrong number or types of arguments in call to
'PR_CONSULTA_DADOS_ROBO' ORA-06550: line 1, colunm 8: PL/SQL:
Statement ignored;
I published the application on another machine (another developer) and also worked;
Some information that I think are necessary:
Visual Studio 2013;
Oracle.DataAcess.dll version 4.121.1.0;
Oracle.ManagedDataAccess.dll version 4.121.1.0;
ISS 7.0;
Pool - Enable 32-bit Applications true;
If you can help me...
Very thanks in advance!
After many trials and errors managed to solve. I do not know if it is the best solution but worked.
In machine.config exists a definition of <oracle.manageddataaccess.client>:
<configSections>
<section name="oracle.manageddataaccess.client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
</configSections>
So I added this declaration in web.config and it worked perfectly.
I had the same issue and this showed me the way to a solution.
The cause of the issue was that I had installed the OracleManagedDataAccessClient through NUGET but someone else had done a native install of the client. When the client was installed, it created an entry in the Machine.Config. When NUGET installed it created an entry in the Web.config. When trying to execute, I received an error that the section for:
<section name="oracle.manageddataaccess.client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
Already existed. I commented it out and my service worked but Oracle would fail with the error:
"PLS-00306: wrong number or types of arguments in call"
When the client was installed it was an earlier version of Oracle so the entry in the Machine.config was:
<section name="oracle.manageddataaccess.client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.**1**.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />
Since I commented the entry in web.config, the application used the machine.config entry which did not match the actual version.
I modified the entry in the machine.config to match the web.config and everything now works.
I looked into following links http://msdn.microsoft.com/en-us/library/windowsazure/gg185668.aspx and http://msdn.microsoft.com/en-us/library/windowsazure/gg185682.aspx
I want to configure Windows Azure Cache (In role Caching). i found that there
are two options Co-located Topology and Dedicated Topology.But i m using co-located i
had configured web.config has shown in link but i couldn't able to do that plz see below
web.config i had configured but i m getting error
I m trying from last 2 days but i could get any soln..thnk you
web.config file
<configSections>
<section name="dataCacheClients"
type="Microsoft.ApplicationServer.Caching.DataCacheClientsSection, Microsoft.ApplicationServer.Caching.Core"
allowLocation="true" allowDefinition="Everywhere" />
<section name="cacheDiagnostics"
type="Microsoft.ApplicationServer.Caching.AzureCommon.DiagnosticsConfigurationSection, Microsoft.ApplicationServer.Caching.AzureCommon"
allowLocation="true" allowDefinition="Everywhere" />
<system.web>
<sessionState mode="Custom" customProvider="AFCacheSessionStateProvider">
<providers>
<add name="AFCacheSessionStateProvider"
type="Microsoft.Web.DistributedCache.DistributedCacheSessionStateStoreProvider, Microsoft.Web.DistributedCache"
cacheName="default" dataCacheClientName="default" applicationName="AFCacheSessionState"/>
</providers>
</sessionState>
</system.web>
<dataCacheClients>
<dataCacheClient name="default">
<autoDiscover isEnabled="true" identifier="WebRole1" />
</dataCacheClient>
</dataCacheClients>
<cacheDiagnostics>
<crashDump dumpLevel="Off" dumpStorageQuotaInMB="100" /></cacheDiagnostics>
</configuration>
Error.png
This is purely because cache client binaries are trying to locate WebRole1 but is unable to do so because probably WebRole1 does not exist. Can you check the cache role name you have given in your configuration ?
Can you show your configuration or share a scaled down repro here ?
I want email to be sent only on a specific condition and log error in DB in all cases. But as I understand, filtering can't work for one of the two. Is that right? If so then how can I achieve it?
Also to note that, right now I'm saving additional info to database on ErrorMail_Mailing in global.asax as replied by Atif Aziz. Because email will be sent only on conditional basis and ErrorMail_Mailing fires only while sending email, I wonder how would I be able to save additional info of all errors to database.
UPDATE:I have modified Elmah code a bit to satisfy my need.
The first step is to configure modules. Make sure you add Elmah.ErrorFilterModule after any of the logging modules from ELMAH, as shown here with ErrorLogModule:
<httpModules>
...
//email
<add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah"/>
//sql
<add name="ErrorSql" type="Elmah.SqlErrorLog, Elmah"/>
<add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah"/>
...
</httpModules>
Then in your configuration section registered Elmah.ErrorFilterSectionHandler as shown here:
<configSections>
<configSections>
<sectionGroup name="elmah">
<section name="errorFilter" type="Elmah.ErrorFilterSectionHandler, Elmah"/>
</sectionGroup>
</configSections>
Now you can add filters to decide what errors to be ignored for what source. The following example shows how to prevent having 404 HTTP errors being mailed.
<elmah>
<errorMail from="xx#xx.com" fromName="xx" to="xx#xx.com" subject="An unhandled exception occured xxx" priority="Normal" async="false" smtpServer="xx.xx.xx.com"/>
//sql
<errorLog name="ErrorSql" type="Elmah.SqlErrorLog, Elmah" connectionStringName="MyConnectionString" />
<add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah"/>
<errorFilter>
<test>
<and>
<equal binding="HttpStatusCode" value="404" type="Int32" />
<regex binding="FilterSourceType.Name" pattern="mail" />
</and>
</test>
</errorFilter>
</elmah>
You can find out more detail information on the following link.
http://code.google.com/p/elmah/wiki/ErrorFiltering
The ELMAH documentation on error filtering has a section on exactly your scenario and is called, which amounts to filtering by source. For example, the following will prevent 404 HTTP errors from being mailed but they will be still logged (assuming both mailing and logging modules are registered):
<errorFilter>
<test>
<and>
<equal binding="HttpStatusCode" value="404" type="Int32" />
<regex binding="FilterSourceType.Name" pattern="mail" />
</and>
</test>
</errorFilter>
If you want to save all exceptions to the database you should just be able to use the ErrorLogModule like so which should be independent of what you are doing in the error mail module:
<add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" preCondition="managedHandler" />
and then in your elmah secition of your config:
<errorLog type="Elmah.SqlErrorLog, Elmah" connectionStringName="MyConnectionString" />
You should try out the StackExchange.Exceptional
This project was inspired by ELMAH, but it didn't suit our particular
needs for very, very high volume error logging when a network-level
event occurs.
StackExchange.Exceptional is the error handler used internally by
Stack Exchange and Stack Overflow for logging to SQL.
It also supports JSON and memory error stores, filtering of exceptions
before logging, and fail/retry mechanisms for storing errors if
there's an interruption in connecting to the error store.
It's highly customizable and it's really easy to add something according your needs.
As i can see an pull request has the email functionality implemented Email functionality so you can start from there.
To set it up you only need to look at the web.config and pick what to enable.
Hope it helps.