Release Notes

EventStoreDB 5.0.1

Shaan Nobee  |  06 May 2019

EventStoreDB 5.0.1 is out! It is available for the following operating systems:

  • Windows
  • Ubuntu 18.04
  • Ubuntu 16.04
  • Ubuntu 14.04
  • macOS 10.9+
  • CentOS 7 (Commercial version)
  • Amazon Linux AMI (Commercial version)

This release comes with some critical bug fixes and we highly recommend our users to upgrade as soon as possible. We’re also planning to roll out version 4.1.3 with a subset of these bug fixes within the next few days.

Where can I get the packages?

Downloads are available on our website.

The packages can be installed using the following instructions.

Ubuntu 14.04/16.04/18.04 (via packagecloud)

curl -s | sudo bash
sudo apt-get install eventstore-oss=5.0.1-1

Windows (via Chocolatey)

choco install eventstore-oss -version 5.0.1

Client Packages
EventStore Client
There are no updates to EventStore.Client with this release. The latest version can be installed with:

dotnet add package EventStore.Client --version 5.0.1

EventStore Embedded Client
There are no updates to EventStore.Client.Embedded with this release. However, we have bumped up the version from 5.0.0 to 5.0.1 to align the client & server versions.

dotnet add package EventStore.Client.Embedded --version 5.0.1

Upgrade Procedure (Important)

The behaviour of the $by_category, $by_correlation_id and multi-stream JavaScript projections has changed and thus it is important to follow the steps below during an upgrade.

  1. Stop all projections. This will force the projections to write a checkpoint and when the node is restarted, events up to the checkpoint will not be processed again.
  2. Do a rolling upgrade as usual: Stop, upgrade and launch one node at a time starting with slave nodes, then the master.

If you do not follow Step 1, your projections may fault with the following error and you will need to either reset the projection or manually adjust the checkpoint:

An event emitted in recovery for stream <stream> differs from the originally emitted event. Existing('<event type>', '<caused by tag>'). New('<event type>', '<caused by tag>')

Event Store 5.0.1 Changelog

Critical Bug Fixes

  • #1915 - (Core Database) Fix idempotent writes for cases where events have not yet been replicated
    This bug can cause the loss of events during idempotent writes. Here’s a scenario of how it can happen in a 3-node cluster:
    1. A client retries a write due to a timeout
    2. The master sees the write as an idempotent write and immediately returns Success to the client although the original event write has not yet been replicated to a quorum number of nodes (2 in this case).
    3. Both slave nodes go down and the write never gets replicated (or the same thing happens if there was only one slave node alive at that time and it goes down)
    4. The client assumes that this write was committed due to the Success acknowledgement but the event was lost.
  • #1908 - (Projections) Fix passing of wrong object to _subscriptionDispatcher.Subscribed() call
    This bug can cause multi-stream projections (using fromStreams or fromCategories) to skip processing of an event when the projection is stopped and started.
  • #1920 - (Index) Fix assertion regarding # of midpoints cached
    This bug will prevent EventStore from starting up if no midpoints have been cached in a PTable V4 file. The logs will show the following stack trace:
    Error in TableIndex.ReadOffQueue
    EventStore.Core.Exceptions.CorruptIndexException: Less than 2 midpoints cached in PTable. Index entries: <num index entries>, Midpoints cached: 0
    at EventStore.Core.Index.PTable..ctor(String filename, Guid id, Int32 initialReaders, Int32 maxReaders, Int32 depth, Boolean skipIndexVerify) in
  • #1890 - (Persistent Subscriptions) Persistent subscriptions: Ignore replayed events during checkpointing
    This bug can cause persistent subscriptions to skip events when parked messages are replayed multiple times.

Important Bug Fixes

  • #1914 - (Scavenging) Don’t MarkForDeletion a chunk until all references to it have been swapped (thanks to @lscpike!)
    This bug can cause read errors on the server side when a scavenged chunk is being swapped. A stack trace similar to the following will be printed to the logs:
Error during processing ReadStreamEventsBackward request.
EventStore.Core.Exceptions.FileBeingDeletedException: Been told the file was deleted > MaxRetries times. Probably a problem in db.
  at EventStore.Core.TransactionLog.Chunks.TFChunkReader.TryReadAtInternal (System.Int64 position, System.Int32 retries)
  • #1919 - (User Management) Retry reading from $users-password-notifications stream if the read times out
    This bug prevents user updates (password, group changes and deletions) from taking effect on the node until it is restarted.
  • #1900 - (Projections) Fix $by_category processing of stream deleted events
    This bug fix prevents metadata events from being emitted into $ce-<category> streams except if they are stream deleted metadata events.
  • #1882 - (Projections) Ignore IsJson property in $by_correlation_id projection
    This bug fix allows events having the IsJson property set to false to be processed by the $by_correlation_id projection. The projection will attempt to parse the event data as a JSON object.

Miscellaneous Bug Fixes

  • #1921 - (Projections) Add missing assignment to ProjectionsQueryExpiryDefault (thanks to @mcollins4551!)
  • #1873 - (Monitoring) Write stats csv header when date changes (when stats file rolls over)
  • #1926 - (Monitoring) Increase the slow queue message threshold to 800ms for the MonitoringQueue
  • #1888 - (HTTP API) Do not send Content-Type header when body is empty
  • #1881 - (HTTP API) Try to deserialize data or metadata string to JSON object when writing through HTTP API
  • #1884 - (HTTP API) Handle GET and POST requests on /users endpoints (instead of only /users/)
  • #1918 - (Scavenging) Add regular file flushes whilst writing out scavenged chunk (thanks to @lscpike!)
  • #1886 - (Subscriptions) Fix issue where proto3 clients could not subscribe to $all
  • #1887 - (Windows) Use absolute path as mutex name when starting up node
  • #213 - (UI) Added Placeholder for password field in the login form
  • #214 - (UI) Fix typo
  • #219 - (UI) Parse $state parameters as ints in scavenge view

How do I provide feedback?

We appreciate any feedback via either GitHub Issues or forum.

Photo of Shaan Nobee

Shaan Nobee Shaan joined Event Store in 2017 as a software engineer and works on the core database engine. He is from Mauritius, a beautiful and peaceful island in the Indian Ocean.