This is in reference to the mail sent in the dev mailing list
"Closed parent region present in Hlog.lastSeqWritten".
The sceanrio described is
We had a region that was split into two daughters. When the hlog roll tried to flush the region there was an entry in the HLog.lastSeqWritten that was not flushed or removed from the lastSeqWritten during the parent close.
Because this flush was not happening subsequent flushes were getting blocked
Lets see what happened for the region 2acaf8e3acfd2e8a5825a1f6f0aca4a8
A user triggered split has been issued to this region which can be seen in the above logs.
The flushing of this region has resulted in a seq id 20312223.
The region has been splitted and the parent region has been closed
In the above logs we can also see that the new daugher regions have the next seq id as 20312223 and 20312224.
Now we see that the parent region which was clsoed has a seq id 20312224 which is not flushed.
So further flush are failing as the region is already removed from onlineRegionList.
The doubt here is before the region could be closed, a put has arrived for this region. But due to some reason the flush has not happened for that. We tried to dig this, but not able to get this problem again.
0.90.5 version + few 0.90.6 patches ( before 0.90.6RC0)