Read application log written on Windows Azure

I have 10 applications they have same logic to write the log on a text file located on the application root folder. I have an application which reads the log files of all the applicaiton and shows details in a web page.

Can the same be achieved on Windows Azure? I don't want to use the 'DiagnosticMonitor' API's. As I cannot change logging logic of ap开发者_运维知识库plication.

Thanks, Aman

Even if technically this is possible, this is not advisable as the Fabric Controller can re-create any role at a whim (well - with good reasons, but unpredictable none-the-less) and so whenever this happens you will lose any files stored locally on a role.

So - primarily you should be looking for a different place to store those logs, and there are many options, but all require that you change the logging logic of the application.

You could do this, but aside from the issue Yossi pointed out (the log would be ephemeral; it could get deleted at any time), you'd have a different log file on each role instance (VM). That means when you hit your web page to view the log, you'd see whatever happened to be on the log on that particular VM, instead of what you presumably want (a roll-up of the log files across all VMs).

Windows Azure Diagnostics could help, since you can configure it to copy log files off to blob storage (so no need to change the logging). But honestly I find Diagnostics a bit cumbersome for this. It will end up creating a lot of different blobs, and you'll have to change the log viewer to read all those blobs and combine them.

I personally would suggest writing a separate piece of code that monitors the log file and, for each new line, stores the line as an entity (row) in table storage. This bit of code could be launched as a startup task and just run continuously as a separate process (leaving everything else unchanged). Then modify the log viewer to read the last n entities from table storage and display them.

(I'm assuming you can modify the log viewer even if you can't modify the apps that log to the file.)

What about writing logs to something like azure storage table? Just need to define unique ParitionKey/RowKey, then you can easily retrieve the log for the web page.