Question

I am having a problem and I need your help.

I am working with Play Framework v1.2.4 in java, and my server is uploaded in the Heroku servers.

All works fine, I can access to my databases and all is ok, but I am experiment troubles when I do a couple of saves to the database.

I have a method who store data many times in the database and return a notification to a mobile phone. My problem is that the notification arrives before the database finish to save the data, because when it arrives I request for the update data to the server, and it returns the data without the last update. After a few seconds I have trying to update again, and the data shows correctly, therefore I think there is a time-access problem.
The idea would be that when the databases end to save the data, the server send the notification.

I dont know if this is caused because I am using the free version of the Heroku Servers, but I want to be sure before purchasing it.

Answer 1

In general all requests to cloud databases are always slower than the same working on your local machine. Even simply query that on your computer needs just 0.0001 sec can be as slow as 0.5 sec in the cloud. Reason is simple clouds providers uses shared databases + (geo) replications, which just… cannot be compared to the database accessed only by one program on the same machine.

Also keep in mind that free Heroku DB plans doesn’t offer ANY database cache, which means that every query is fetched from the cloud directly.

As we don’t know your application it’s hard to say what is the bottleneck anyway almost for sure you have at least 3 ways to solve your problem. They are not an alternatives, probably you will need to use (or at least check) all of them.

1. You need to risk some basic plan and see how things changed with paid version, maybe it will be good enough for you, maybe not.
2. Redesign your application to make less queries. For an example instead sending 10 queries to select 10 different rows, you will need to send one query, which selects all 10 records at once.
3. Use Play’s cache API to avoid repeating selecting the same set of data again and again. For an example, if you have some categories, which changes rarely, but you need category tree for each article, you don’t need to fetch categories from DB every time, instead you can store a List of categories in cache, so you will need to use only one request to fetch article’s content (which can be cached for some short time as well…)