At ~ 7am one of db servers stopped responding, and got restarted using AWS console.
After reboot everything seemed to work fine.
But later on I found that one of the segments was not archived.
Segment ...7 was written (mtime of file in pg_xlog) at 6:51 (more or less)
Segment ...8 was written at 6:57
Segment ...9 was written at 7:13
then there were more.
What's interesting - in archive_status, i see .done files for all xlogs, except for ...8. In logs the *8 xlog is not mentioned (I was looking for error message or something).
The xlog didn't make it to destination or archiving, but instead of being retried after reboot - pg moved to *9, and then continued.
I manually archived *8, and everythinh was fine afterwards, but I'm puzzled on how could it happen that an xlog gets skipped? Even in case of force-reboot.
