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Sven 2020-07-27T13:30:17.449600Z

Is it possible to preload multiple databases after instance restart or speed up the initial d/connect? I’d like to deploy ions often but every deployment results in the initial d/connect to a non preloaded db taking 10+ seconds.

Joe Lane 2020-07-27T13:36:33.450200Z

@sl What kind of topology are you using?


@staypufd Using the option "Use tools.deps directly" on a updated Cursive.

Sven 2020-07-27T13:49:12.450600Z

@lanejo01 solo for dev and testing and production for qa and live

Joe Lane 2020-07-27T13:53:15.453200Z

• Is it the same production topology for QA and Live? • How do you know the problem the d/connect time is taking a long time? • Are you sure it's not because of lambda coldstart? • Have you considered using HTTP DIrect?

Joe Lane 2020-07-27T14:03:01.455400Z

@sl I'm not sure how you're measuring the time, but the first thing I would look at is switching to Http Direct if you aren't already using it.

Sven 2020-07-27T14:03:16.455900Z

1) yes. Though the issue is way more pronounced on solo. 3) lambda cold starts occasionally contribute to the issue but I run lambda warmers to help mitigate this 4) I am using appsync so I have to invoke lambdas

Joe Lane 2020-07-27T14:05:29.458900Z

3) I think that lambdas are rebuilt on redeploy so I'm not sure your warmers would be able to help 4) Doesn't appsync also support an http proxy?

Sven 2020-07-27T14:33:42.464500Z

hmmm, I have somehow completely missed ions with HTTP direct. I’ll do some testing on production topology. Thanks for that tip! 2) as of d/connect taking a long time - when I manually reboot the solo topology instance and after restart connect to that system from my laptop (bypassing the lambda function altogether) then the first connect +query/transaction takes a long time.


With dev-local, what are the limitations about storage, number of transactors and readers?


Thanks Stuart!

kschltz 2020-07-27T15:07:38.466600Z

Hi there, I've heard rumours about datomic cloud support for cross db queries, do you guys know something about this? Any reading material on the subject is more than welcome

Joe Lane 2020-07-27T16:05:23.467800Z

Cross DB queries in cloud refers to the same db at two different points on it's timeline, not two different databases across timeline's.

stuarthalloway 2020-07-27T16:30:41.467900Z

Hi David. dev-local is in process, so there are no transactors. Memory usage is described at https://docs.datomic.com/cloud/dev-local.html#limitations.

kschltz 2020-07-27T17:09:37.468100Z

I see, given that I have db-A and db-B, isn't there any built-in features to support simultaneous queries in both bases?

kschltz 2020-07-27T21:36:31.469900Z

Other thing that isn't very clear to me regarding datomic cloud. Suppose I have a production topology with several dbs, would the write ops interfere with one another among those databases or are they served by different transactors?

Joe Lane 2020-07-27T23:05:48.470900Z

@schultzkaue Different transactors. They would not compete for resources in the way you described.

stuarthalloway 2020-07-28T16:43:52.486100Z

I would just add that you can increase the number of processes in the primary compute group if you have many databases: https://docs.datomic.com/cloud/operation/scaling.html#database-scaling

kschltz 2020-07-29T14:24:14.494400Z

That would be a perfect fit

kschltz 2020-07-29T14:24:20.494600Z


kschltz 2020-07-27T23:26:58.471Z

Great, thanks