Re: Is it safe enough to write edit log in buffer before writing to disk ?

Thanks, Todd. I saw the flush code. On Fri, Jun 11, 2010 at 9:31 AM, Todd Lipcon wrote: > Hi Jeff, > All of the FSNamesystem methods call logSync() before returning to the > client. So, if the edit is lost, it also will not have returned a success to > the client. > -Todd > > On Thu, Jun 10, 20

Re: Is it safe enough to write edit log in buffer before writing to disk ?

Hi Jeff, All of the FSNamesystem methods call logSync() before returning to the client. So, if the edit is lost, it also will not have returned a success to the client. -Todd On Thu, Jun 10, 2010 at 6:29 PM, Jeff Zhang wrote: > Hi all, > > I check the source code of EditLogFileOutputStream, it

Is it safe enough to write edit log in buffer before writing to disk ?

Hi all, I check the source code of EditLogFileOutputStream, it seems hadoop will first write edit log to buffer, then flush to disk. I know that it will improve performance, but in the other hand it will cause the edit log in buffer lost when the name node is down. So I wonder is it possible and n