does forwarders put a lock on a log file while forwarding?

[firasarabo]

Hi,
I need to know how splunk forwarders works. does it put a lock on the log file while reading it and while forwarding data to the indexers? I guess not but wanted to make sure.

[ea7777777]

Hi, an old topic.. but I have exactly that poblem.

Here my Inputs.conf

[monitor://D:\daten\Splunk\Abgleich1]
index = rbg_ff1_line_prodel_EPL1
sourcetype = rbg_ff1_line_prodel_EPL1_adjust_1
crcSalt = <SOURCE>
followTail = 1 

The actual process:

• An PLC creates and fills up an text file
• PLC writes very fast step by step 8 lines in the text file. Each line is an component. The writing process stops after each line and starts again with the next one.
• An universal forwarder grabs that text file.

Now my problem:

• The PLC cannot write to the text file every 20-100 write cycles. Error code is "text file allready opened by another process"
• The reason for this is, that the universal forwarder is currently reading the file
• The proof of this is, as soon as I deactivate the UF, the PLC writes all data without any problems

The UF does not block as long as it is only monitoring the file. But when it starts reading the file, it bocks the PLC to write on it.

What options do I have to prevent this?

[Drainy]

No it doesn't.
It will forward the contents the first time it is run and will then monitor it for any further changes, access to the log file by other services is allowed and completely un-impeded during this 🙂