Seq 5.1 Release

We've spent four solid months extending and refining Seq 5. TL/DR? Download the Seq 5.1 installer for Windows or pull datalust/seq from Docker Hub.

Seq 5.1

What is Seq?

Seq is a log server designed specifically for structured log data. At its core, Seq combines a JSON data model with text search and a simple SQL-style query language. On this foundation, Seq builds the diagnostics, dashboarding, and alerting capabilities needed by modern development and operations teams.

What's new in Seq 5.1?

Seq 5.0 was a game-changing, giant leap kind of release: new platform support (Docker/Linux), new native storage engine with signal indexing, new .NET runtime (.NET Core), new look and feel 😎, workspaces, and more. Just shipping it was, to us, a quiet marvel, and when it came to release day, the rough edges were small in comparison with all the new things Seq gained.

With that behind us, though, we started noticing where 5.0 stopped short. We rolled up our sleeves and set out to fill some gaps, and along the way, we realized that the earlier version left a lot of low-hanging fruit: new possibilities, easy extensions to new features, and simple ergonomic improvements.

  • Faster correlation id searches became pre-filtering, an up-to-10× speedup for all text-based, and many property-value, searches from disk,
  • A review of workspaces led to a more usable signal bar (+N more), and, a visually obvious namespace / convention for distinguishing shared from personal items,
  • GELF ingestion for Docker became a whole new pluggable input mechanism, supporting not just GELF but RabbitMQ and soon Azure Event Hubs, and enabling new use cases like health checks,
  • The new roles/permissions security model let us introduce read-only user roles, and login-free dashboads,
  • Dashboards got table-valued charts and a new mouse-over correlation line, and,
  • Manageability in Docker led to environment variables now being available to set or override any configuration item from Seq.json.

The full release notes on GitHub list 38 new features and bug fixes added in the 5.1 milestone. We'll write about many of these in more detail over the coming weeks.

On top of this, we think Seq 5.1 is really, really solid. During the 5.1 development cycle, we profiled and tuned everything from connection limits and timeouts in the HTTP stack, to GC settings, to behavior under I/O saturation, and more. We've added better circuit breakers, an indexer throttle, caching in front of the document store, more internal metrics... Heaps of edge cases have been examined, and stablility improved across the board.

Getting Seq 5.1

Seq 5.1 is a highly-backwards-compatible, in-place upgrade, with no significant breaking changes. Detailed upgrade notes are being maintained in the Seq 5.1 documentation.

Windows users can install the Seq 5.1 MSI from the downloads page.

Linux/macOS users can update Docker instances to the datalust/seq:latest or datalust/seq:5 tags, or a specific build listed on Docker Hub.

As always, if you have more questions or need help upgrading, please get in touch via Happy logging!

Nicholas Blumhardt

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