We are monitoring a file name X.log witch contain similar structure for events starting by a date format. The number of events that were indexed in Splunk are less than the number of events in the file. Is there any bug in indexing ? what logs should i look at ?
It is also possible that your timestamping is off and some of your events are showing up way at the wrong time (even in the future). Try this search run for ALL TIME (you have to use "ALL TIME" because that is the only way to search for events "in the future):
index=myIndex sourcetype=mySourceType | eval bytes=len(_raw) | stats count sum(bytes) by source
This will allow you to compare against your sourcefiles with this linux CLI:
cat myFile | wc
If the bytes match, then all of your file is going into Splunk. If the "count" equals "lines" then all the lines are broken correctly.
If your events are single line it is possible that Splunk has combined some of them accidentally. You can configure event line breaking by following the guidance here --> http://docs.splunk.com/Documentation/Splunk/6.2.2/Data/Indexmulti-lineevents
In your case you may be most interested in the BREAK_ONLY_BEFORE parameter.