Implementing Splunk 7, Third Edition - Third Edition

When to use crcSalt

To keep track of what files have been seen before, Splunk stores a checksum of the first 256 bytes of each file it sees. This is usually plenty as most files start with a log message, which is almost guaranteed to be unique. This breaks down when the first 256 bytes are not unique on the same server.

I have seen two cases where this happens, as follows:

1. The first case is when logs start with a common header containing information about the product version, for instance:

================================================================ 
== Great product version 1.2 brought to you by Great company == 
== Server kernel version 3.2.1 == 

2. The second case is when a server writes many thousands of files with low time resolution, ...