how to monitor file access by app

[Kenny_Yu]

How to see what files a java application is accessing, especially, writing? I figure this is possible, but I am missing it, because appd can detect backend activities such as jms and jdbc. Thanks.

[Jean-Baptiste_M]

Hi Kyu
I would do it by defining a custom exit point on the right class/method
making the file read or write. A single exit point (without split) should
be enough and you can collect additional information such as filename as a
snapshot data

https://docs.appdynamics.com/display/PRO42/Configure+Custom+Exit+Points

You would see the icon on the flow map

Or you could go with a Data Collector:

https://docs.appdynamics.com/display/PRO42/Collecting+Application+Data

You could search for a specific filename but only for BTs with a snapshot

So it all depends on what you need.
Best
JB

[Kenny_Yu]

Hi, JB,

Those are interesting ideas and would work if I had access to the code. The application I am dealing with is a blackbox that writes log/tmp files to locations that are dynamically set and have randomized pathnames. I'll need to grab stacktraces to identify the classname.methodname, but even that won't work if the classes are loaded dynamically from the network via a custom classloader.

Cheers

K

[Jean-Baptiste_M]

then lsof is your only remaining friend, isn't it?

[Kenny_Yu]

JB,

lsof will work - but do I have to log in to the host or can appd help?

Thanks

Kenny

[Jean-Baptiste_M]

Hmm,
You can use a custom extension
https://docs.appdynamics.com/display/PRO42/Extensions+and+Custom+Metrics to
automate a script using lsof, but the extension cannot retrieve any list
only counters (number of files for examples)
You can use your scrip to copy the list somewhere.
Or you can use Log Analytics to do that but you need a specific license.
Let me know what you think
JB