No problem. It's definitely a subtlety. It occurs because each partition is processed completely independently of the others, so "stream time" is tracked per partition, and there's no way to look across at the other partitions to find out what stream time they have.
In general, it's not a problem because you'd expect all partitions to receive updates over time, but if you're specifically trying to send events that cause stuff to get flushed from the buffers, it can mess with you. It's especially notable in tests. So, for most tests, I just configure the topics to have one partition. -John On Fri, Jun 21, 2019 at 3:56 PM Parthasarathy, Mohan <mpart...@hpe.com> wrote: > > That change "In the same partition" must explain what we are seeing. Unless > you see one message per partition, all windows will not expire. That is an > interesting twist. Thanks for the correction ( I will go back and confirm > this. > > -mohan > > > On 6/21/19, 12:40 PM, "John Roesler" <j...@confluent.io> wrote: > > 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 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
