Is there any way to emulate the behavior of the tx-report-queue in this code snippet with datomic-cloud?

(defn react-on-transactions! [conn]
  (let [tx-queue (d/tx-report-queue conn)]
    (thread
      (while true
        (let [txn (.take tx-queue)]
          (try
            (when (:tx-data txn)
              (on-transaction txn))
            (catch Exception e
              (log/error e "There was an error diring processing of datomic transaction"))))))))

So I read above, found the approach that @luchini was suggested with tx-log and I’m going through https://github.com/cognitect-labs/day-of-datomic-cloud searching for usages of tx-log. Maybe polling for transactions since the last basis-t is the best approach here.

Is there anyway to speculativly transact fixtures into a db using d/withthat a transaction function can be tested with?

Hey folks. Is it possible to store small data structures as values without converting them to a byte array or string? For instance

[?entity-id :some/attribute {:a 1 :b 2} ?transaction_id]

If so, what is the :db/valueType to use for such a thing? (The lack of an obvious answer to that makes me think that I would have to convert to byte array or string).

@chrjs not possible at present, but there are probably feature requests for that. My approach is to serialize as EDN, JSON or Fressian, my choice depending of the requirements in terms of availability, speed and readability of these various formats

Ok, great, thanks @val_waeselynck :thumbsup:

Has anyone standing up or updating a recent on-prem-flavor CloudFormation stack run into this: instances refuse to converge, stopping right at launch, and in the system log is

Cloud-init v. 0.7.6 finished at Thu, 01 Feb 2018 19:30:16 +0000. Datasource DataSourceEc2.  Up 18.22 seconds
mount: special device /dev/sdb does not exist
Stopping sshd:  [  OK  ]

After which the datomic .zip gets downloaded successfully, but startup.sh appears to silently die and then the machine begins orderly shutdown

Not sure if startup.sh is failing or the box is just kindly letting the download finish while stopping

@chris_johnson the most common cause of transactor startup failure is license expired or key put in improperly

It looks correct but I am re-building the template JSON “from scratch” just to make sure

and you’re certain your license is valid for the version you’re running?

you can test it by trying to launch that same version locally with the same properties file

*by same i mean of course with a different storage 🙂

however, if you have AWS creds locally, you could also run a local transactor against your Dynamo storage to make sure that all works as well

@marshall Who do I talk to if I think a license should be valid for the latest version of Datomic Pro and the license validator disagrees? 😇

that would be me 🙂 Can you send me an email?

<mailto:[email protected]|[email protected]>

what's the most efficient way of returning the last 10 transactions for a particular query?