Event Store logo

sss https://eventstore.org Menu

Developer Blog

Event Store 3.0.0 - In-Memory Mode

  |   Written by: James Nugent   |   News

As we gear up to launch version 3.0.0 of Event Store at our annual birthday party (which you should totally come to!), we decided it would be a good idea to run a short series of articles describing some of the new features for those who haven’t seen them. If there are things you want to know about in particular, please get in touch on Twitter, @eventstore!

##In-Memory Mode

One of the common questions about version 2.0.1 of Event Store was how to write tests against it. The new in-memory mode of version 3.0.0 is one part of the answer to that question - at least for integration tests. Unit tests (for example of command handlers) are still likely to be better off testing with a fake version of something like a repository abstraction.

In-memory mode allows for the Event Store server to function normally (including projections and clustering), but with the transaction file and index to be kept entirely in memory instead of writing to disk. This makes it very straightforward to perform integration testing against an actual Event Store server rather than relying on a test double which could have behaviour divergent from that of the server.

In order to start the server in in-memory mode, the --mem-db flag can be passed at the command line, MemDb: true can be specified in the configuration file, or the EVENTSTORE_MEM_DB environment variable can be set to true (or 1 since commit bb8d6a9).

Remember that all data is lost when the server terminates when running in-memory mode!!!


Subscribe to the Event Store blog

Get the latest news and tutorials when they are released

You might also like

    Event Store mentioned in 3 Gartner Reports as Event Driven Architecture vendor

      |   Written by: Dave Remy   |   News

    For the past few years now Gartner Group has been mentioning the critical importance of Event Driven Architecture to the modern enterprise (one of the top 10 trends). Event Store are pleased to be listed in 3 recent reports by Gartner as one of the vendors, along with Amazon Web Services, Confluent, Google, IBM, and others who are offering Event Driven Architecture enabling technology. The three Gartner reports are (Note viewing the full reports require...

    Read article

    Video of Ouro’s 2nd Birthday

      |   Written by: Dan Leech   |   News

    In September we held a party in London to celebrate the company—and more importantly our mascot, Ouro—turning two years old. At the party we showed off version 3.0.0 of Event Store. We also gave the stage to four of our community members to share their experience of developing their projects with Event Store. The video of this event is no longer available.

    Read article

    Event Store 3.0.0 - Configuration Changes

      |   Written by: James Nugent   |   News

    As we gear up to launch version 3.0.0 of Event Store at our annual birthday party (which you should totally come to!), we decided it would be a good idea to run a short series of articles describing some of the new features and changes for those who haven’t seen them. If there are things you want to know about in particular, please get in touch on Twitter, @eventstore ##Configuration Changes Since version 1 of...

    Read article