RE: reverse trace [was: vmware's replay framework and gdb]

Jakob Engblom
2008-11-06T17:09:52Z

> One of the reasons I was thinking of relational databases was that they can
> deal with the volume and put whatever the decide to cache into dis instead of
> memory (but maybe you were thinking disk space when you said memory anyway).

RAM, disk, does not matter -- size is enormous either case.

> Besides compression of data stream there is also the possibility of only
> caching at certain sync points and tracing between sync points you have to
> regenerate the temp variables, etc. Like I said, I was just brain storming
> here. I had no idea how far things had gotten along the lines of
> Chronomancer/Chronicle.
>
> Regardless of how it eventually ends up working, it is going to either use a
> LOT of space, or a lot of CPU power to recreate.

The CPU power is actually easier to handle, especially if you have a few
snapshots to return to along the way. We have looked at this hard, and the
execution to recreate is much easier to make scalable than the complete trace
approach.

/jakob