have run into the bottleneck of the driver's IO thread. Try
> increase the driver's connections-per-server limit to 2 or 3 if you've only
> got 1 server in the cluster. Or alternatively, run two client processes in
> parallel.
>
>
> On 24/04/2024 07:19, Nathan Marz wrote:
>
> Tr
mplicit limits on the
> number of in-flight requests, which default to 1024 requests per connection
> and 1 connection per server. See
> https://docs.datastax.com/en/developer/java-driver/4.17/manual/core/pooling/
>
>
> On 23/04/2024 23:18, Nathan Marz wrote:
>
> It's using the a
<
user@cassandra.apache.org> wrote:
> Have you checked the thread CPU utilisation of the client side? You likely
> will need more than one thread to do insertion in a loop to achieve tens of
> thousands of inserts per second.
>
>
> On 23/04/2024 21:55, Nathan Marz wrote:
>
&
itlog at shorter intervals and allow more concurrent writes.
>
>
> On 23/04/2024 20:43, Nathan Marz wrote:
>
> Thanks. I raised concurrent_writes to 128 and
> set commitlog_sync_group_window to 20ms. This causes a single execute of a
> BatchStatement containing
rease the value of
> concurrent_writes, consider at least double or quadruple it from the
> default. You'll need even higher write concurrency for longer
> commitlog_sync_group_window.
>
> On 23/04/2024 19:26, Nathan Marz wrote:
>
> "batch" mode works fine. I'm havin
e the writer threads will be
> unable to do extra work while waiting. You may need to increase
> concurrent_writes for the same reason*
>
> If you want to use batch mode, at least ensure commitlog_sync_batch_window
> is reasonably short. The default is 2 millisecond.
>
>
>
I'm doing some benchmarking of Cassandra on a single m6gd.large instance.
It works fine with periodic or batch commitlog_sync options, but I'm having
tons of issues when I change it to "group". I have
"commitlog_sync_group_window" set to 1000ms.
My client is doing writes like this (pseudocode):
