How does a Splunk forwarder read a file?

[skoelpin]

We are constantly writing to a file and cannot have the file open as it's being written to.

What permissions does a Splunk forwarder need to forward data?

Does a Splunk forwarder "open" the file to read its contents?

[inventsekar]

How Splunk Enteprise monitors nonwritable Windows files
Windows can prevent Splunk from reading open files. If you need to read files while they are being written to, you can use the monitorNoHandle input.

Why use MonitorNoHandle?
This Windows-only input lets you read files on Windows systems as Windows writes to them. It does this by using a kernel-mode filter driver to capture raw data as it gets written to the file. Use this input stanza on files which get locked open for writing. You can use this input stanza on a file which the system locks open for writing, such as the Windows DNS server log file.

Note: MonitorNoHandle only works on Windows Vista or Windows Server 2008 and later operating systems. You can only monitor single files with MonitorNoHandle. You can not monitor directories. If a file you choose to monitor already exists, Splunk does not index its current contents, only new information that comes into the file as it gets written to.

from - http://docs.splunk.com/Documentation/Splunk/6.4.2/Data/Monitorfilesanddirectories

[ddrillic · Accepted solution]

On Linux, it needs the read permission. The following explains it - Permissions on /var/log

[skoelpin]

What about a Windows server?

[somesoni2]

Same. Read permission