Fork me on GitHub
Björn Ebbinghaus15:07:35

Is it wise to store sequential data in datomic? Like a log. I need to store sequences of sequences of events. Like this:

{:user1 [[:a :b] [:a :b :c]]
 :user2 [[:b :c]]}


hi @U4VT24ZM3! There is some discussion of patterns for sequential data at


My clj tool can't seem to download the com.datomic/ion jar from S3. Even if I directly clone the ion-starter project and then try to run clj, it gets a 403 from Amazon S3:

$ git clone  && cd ion-starter
$ clj
Error building classpath. Failed to read artifact descriptor for com.datomic:ion:jar:0.9.16
org.eclipse.aether.resolution.ArtifactDescriptorException: Failed to read artifact descriptor for com.datomic:ion:jar:0.9.16
Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Could not transfer artifact com.datomic:ion:pom:0.9.16 from/to datomic-cloud (): Access Denied (Service: Amazon S3; Status Code: 403; Error Code: AccessDenied; Request ID: 6F26D77435731E93; S3 Extended Request ID: bcJFpRXI081lRtaNVQeMMyrTWhU+wbqWfwOk/YjCD+m5t0mfCwHFWcGdqVYAbMK75k5S4Ei9Y4M=)
        at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(


ok looks like it was an AWS permission issue. My user was in the datomic-admin-<system name> group but evidently that's not enough, I gave it the AdministratorAccess policy and now it works 👍. Figuring out exactly which permission was missing is an exercise for later, I guess 😁


is it possible to deploy multiple ions applications to the same datomic cloud system? I suppose they would at least have to have the same name, since you can't do a push if the ions application name doesn't match the system's application name


@miridius in my experience you can, though you might need to have one top-level ion-config.edn that knows about all the applications


how does that work exactly? I think i tried, setting :app-name to something arbitrary and it didn’t seem to like that