Sure, the record cache attempts to save downstream operators from unnecessary updates by also buffering for a short amount of time before forwarding. It forwards results whenever the cache fills up or whenever there is a commit. If you're happy to wait at least "commit interval" amount of time for updates, then you don't need to do anything, but if you're on the edge of your seat, waiting for these results, you can set cache.max.bytes.buffering to 0 to disable the record cache entirely. Note that this would hurt throughput in general, though.
Just a slight modification: * a new record with new timestamp > (all the previous timestamps + grace period) will cause all the old windows *in the same partition* to close * yes, expiry of the window depends only on the event time Hope this helps! -John On Thu, Jun 20, 2019 at 11:42 AM Parthasarathy, Mohan <mpart...@hpe.com> wrote: > > Could you tell me a little more about the delays about the record caches and > how I can disable it ? > > If I could summarize my problem: > > -A new record with a new timestamp > all records sent before, I expect *all* > of the old windows to close > -Expiry of the windows depends only on the event time and not on the key > > Are these two statements correct ? > > Thanks > Mohan > > On 6/20/19, 9:17 AM, "John Roesler" <j...@confluent.io> wrote: > > Hi! > > In addition to setting the grace period to zero (or some small > number), you should also consider the delays introduced by record > caches upstream of the suppression. If you're closely watching the > timing of records going into and coming out of the topology, this > might also spoil your expectations. You could always disable the > record cache to make the system more predictable (although this would > hurt throughput in production). > > Thanks, > -John > > On Wed, Jun 19, 2019 at 3:01 PM Parthasarathy, Mohan <mpart...@hpe.com> > wrote: > > > > We do explicitly set the grace period to zero. I am going to try the > new version > > > > -mohan > > > > > > On 6/19/19, 12:50 PM, "Parthasarathy, Mohan" <mpart...@hpe.com> wrote: > > > > Thanks. We will give it a shot. > > > > On 6/19/19, 12:42 PM, "Bruno Cadonna" <br...@confluent.io> wrote: > > > > Hi Mohan, > > > > I realized that my previous statement was not clear. With a > grace > > period of 12 hour, suppress would wait for late events until > stream > > time has advanced 12 hours before a result would be emitted. > > > > Best, > > Bruno > > > > On Wed, Jun 19, 2019 at 9:21 PM Bruno Cadonna > <br...@confluent.io> wrote: > > > > > > Hi Mohan, > > > > > > if you do not set a grace period, the grace period defaults > to 12 > > > hours. Hence, suppress would wait for an event that occurs 12 > hour > > > later before it outputs a result. Try to explicitly set the > grace > > > period to 0 and let us know if it worked. > > > > > > If it still does not work, upgrade to version 2.2.1 if it is > possible > > > for you. We had a couple of bugs in suppress recently that > are fixed > > > in that version. > > > > > > Best, > > > Bruno > > > > > > On Wed, Jun 19, 2019 at 8:37 PM Parthasarathy, Mohan > <mpart...@hpe.com> wrote: > > > > > > > > No, I have not set any grace period. Is that mandatory ? > Have you seen problems with suppress and windows expiring ? > > > > > > > > Thanks > > > > Mohan > > > > > > > > On 6/19/19, 12:41 AM, "Bruno Cadonna" <br...@confluent.io> > wrote: > > > > > > > > Hi Mohan, > > > > > > > > Did you set a grace period on the window? > > > > > > > > Best, > > > > Bruno > > > > > > > > On Tue, Jun 18, 2019 at 2:04 AM Parthasarathy, Mohan > <mpart...@hpe.com> wrote: > > > > > > > > > > On further debugging, what we are seeing is that > windows are expiring rather randomly as new messages are being processed. . > We tested with new key for every new message. We waited for the window time > before replaying new messages. Sometimes a new message would come in and > create state. It takes several messages to make some of the old windows to be > closed (go past suppress to the next stage). We have also seen where one of > them never closed even but several other older ones expired. Then we > explicitly sent a message with the same old key and then it showed up. Also, > for every new message, only one of the previous window expires even though > there are several pending. > > > > > > > > > > If we don't use suppress, then there is never an > issue. With suppress, the behavior we are seeing is weird. We are using 2.1.0 > version in DSL mode. Any clues on what we could be missing ? Why isn't there > an order in the way windows are closed ? As event time progresses by the new > messages arriving, the older ones should expire. Is that right understanding > or not ? > > > > > > > > > > Thanks > > > > > Mohan > > > > > > > > > > On 6/17/19, 3:43 PM, "Parthasarathy, Mohan" > <mpart...@hpe.com> wrote: > > > > > > > > > > Hi, > > > > > > > > > > We are using suppress in the application. We see > some state being created at some point in time. Now there is no new data for > a day or two. We send new data but the old window of data (where we see the > state being created) is not closing i.e not seeing it go through suppress and > on to the next stage. It is as though the state created earlier was purged. > Is this possible ? > > > > > > > > > > Thanks > > > > > Mohan > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
