To be clear: to lose data in the filesystem you need to hard kill the machine. A hard kill of the process will not cause that.
-Jay On Tue, Feb 19, 2013 at 8:25 AM, Jun Rao <[email protected]> wrote: > Jason, > > Although messages are always written to the log segment file, they > initially are only in the file system's pagecache. As Swapnil mentioned > earlier, messages are flushed to disk periodically. If you do a clean > shutdown (kill -15), we close all log file, which should flush all dirty > data to disk. If you do a hard kill or your machine just crashed, the > unflushed data may be lost. The data that you saw in the .log file can be > just in the pagecache. > > Thanks, > > Jun > > On Tue, Feb 19, 2013 at 4:05 AM, Jason Huang <[email protected]> wrote: > >> Thanks for response. >> >> My confusion is that - once I see the message content in the .log >> file, doesn't that mean the message has already been flushed to the >> hard drive? Why would those messages still get lost if someone >> manually kill the process (or if the server crashes unexpectedly)? >> >> Jason >> >> On Tue, Feb 19, 2013 at 6:53 AM, Swapnil Ghike <[email protected]> >> wrote: >> > Correction - The flush happens based on *number of messages* and time >> > limits, whichever is hit first. >> > >> > >> > >> > On 2/19/13 3:50 AM, "Swapnil Ghike" <[email protected]> wrote: >> > >> >>The flush happens based on size and time limits, >> >>whichever is hit first. >> > >>
