Log4net Appender to Azure Document Db - azure

Question

I am trying to write a custom appender for Log4net by referring the article http://korrozia.blogspot.in/2016/11/how-to-store-log4net-messages-to-azure.html. Documents are getting created in Azure Doc DB, but the log message is not appearing in document. Below is my custom appender code
public class DocumentDbAppender: AppenderSkeleton
{
private DocumentClient client;
public string DatabaseId
{
get;
set;
}
public string CollectionId
{
get;
set;
}
public string EndpointUrl
{
get;
set;
}
public string AuthKey
{
get;
set;
}
protected override void Append(LoggingEvent loggingEvent)
{
try
{
using (client = new DocumentClient(new Uri(EndpointUrl), AuthKey))
{
var database = RetrieveOrCreateDatabaseAsync(DatabaseId).Result;
var collection = RetrieveOrCreateCollectionAsync(database.SelfLink,
CollectionId).Result;
var document = CreateDocumentAsync(client, collection.SelfLink, loggingEvent).Result;
}
}
catch (DocumentClientException de)
{
Exception baseException = de.GetBaseException();
Debug.Print("Status code {0} error occurred: {1}, Message: {2}", de.StatusCode,
de.Message, baseException.Message);
}
catch (Exception e)
{
Exception baseException = e.GetBaseException();
Debug.Print("Error: {0}, Message: {1}", e.Message, baseException.Message);
}
}
private async Task<Database> RetrieveOrCreateDatabaseAsync(string id)
{
// Try to retrieve the database (Microsoft.Azure.Documents.Database) whose Id is equal to databaseId
var database = client.CreateDatabaseQuery().Where(db => db.Id == DatabaseId).
AsEnumerable().FirstOrDefault();
// If the previous call didn't return a Database, it is necessary to create it
if (database == null)
{
database = await client.CreateDatabaseAsync(new Database { Id = DatabaseId }).ConfigureAwait(false);
Debug.Print("Created Database: id - {0} and selfLink - {1}", database.Id, database.SelfLink);
}
return database;
}
private async Task<DocumentCollection> RetrieveOrCreateCollectionAsync(string databaseSelfLink,
string id)
{
// Try to retrieve the collection (Microsoft.Azure.Documents.DocumentCollection) whose
// Id is equal to collectionId
var collection = client.CreateDocumentCollectionQuery(databaseSelfLink).
Where(c => c.Id == id).ToArray().FirstOrDefault();
// If the previous call didn't return a Collection, it is necessary to create it
if (collection == null)
{
collection = await client.CreateDocumentCollectionAsync(databaseSelfLink,
new DocumentCollection { Id = id }).ConfigureAwait(false);
}
return collection;
}
private async Task<Document> CreateDocumentAsync(DocumentClient client,
string collectionSelfLink, LoggingEvent loggingEvent)
{
var doc = await client.CreateDocumentAsync(collectionSelfLink,
loggingEvent).ConfigureAwait(false);
return doc;
}
}
My Web.config looks like below
<log4net>
<!--This is for local testing. Comment out this appender when moved to azure cloud-->
<!--<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<file value=".\\Logs\\WebApi.log"/>
<appendToFile value="true"/>
<rollingStyle value="Size"/>
<maxSizeRollBackups value="10"/>
<maximumFileSize value="10MB"/>
<staticLogFileName value="true"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%-5p %d %5rms %-22.22c{1} %-18.25M - %m%n"/>
</layout>
</appender>-->
<appender name="DocumentDbAppender"
type="MyApp.Infra.Logger.DocumentDbAppender, MyApp.Infra.Logger">
<DatabaseId>Diagnostics</DatabaseId>
<CollectionId>Logs</CollectionId>
<EndpointUrl>https://mydb.documents.azure.com:443/</EndpointUrl>
<AuthKey>UB0w==</AuthKey>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%-5p %d %5rms %-22.22c{1} %-18.25M - %m%n"/>
<!--<conversionPattern value="%m"/>-->
</layout>
</appender>
I am creating logger instance as below
log4net.Util.LogLog.InternalDebugging = true;
log4net.Config.XmlConfigurator.Configure();
log4netLogger = log4net.LogManager.GetLogger(
System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
If I simply writes a info message, it looks like below in Document DB
{
"$type": "log4net.Core.LoggingEvent, log4net",
"LoggerName": MyApp.Infra.Logger.Log4NetLogger",
"Level": {
"$type": "log4net.Core.Level, log4net",
"Name": "INFO",
"Value": 40000,
"DisplayName": "INFO"
},
"Message": null,
"ThreadName": null,
"TimeStamp": "2017-03-20T15:57:17.7133358+05:30",
"LocationInfo": null,
"UserName": null,
"ExceptionString": null,
"Properties": null,
"Domain": null,
"Identity": null,
"id": "23071629-d896-4812-9a87-89871d969780"
}
Please note that Message is null. I am not sure why it is happening. If I use a Rolling File Appender, I am able to get the message without any issue.

Answer 1

From the link that you provided, we could find it overrides Append method and create a document for LoggingEvent object by using the CreateDocumentAsync method in Append method. Please try to check if Exception object ex is null when you write info message.
LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType).Info("info mes", ex);
Besides, please set breakpoint inside Append(LoggingEvent loggingEvent) method to watch the properties of loggingEvent before you call CreateDocumentAsync method to create the document.