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Comparison · DevOps

Dapr vs Undertow

A side-by-side editorial comparison of Dapr and Undertow — release velocity, themes, recent moves, and the top alternatives to consider.

Dapr vs Undertow: at a glance

FeatureDaprUndertow
SectorDevOpsDevOps
Velocity score5.00.0
Sparks · 30d00
Top themesworkflows, actors, maintenance, backportshttp-server, java, http2, cve-fixes
Last editorial update9h ago2h ago
WebsiteVisit →Visit →

What is Dapr?

Dapr is running three maintenance branches at once and shipping no new surface.

Dapr is maintaining 1.16, 1.17 and 1.18 in parallel, with 1.18.3 currently working through release candidates. The recent window is entirely correctness and supply-chain work: workflow recovery, actor reminder registration, scheduler stream handling, an input-binding probe timeout, and Go and dependency bumps for reported CVEs. The same fixes appear repeatedly across branches as backports rather than as distinct changes.

Read the full Dapr trajectory →

What is Undertow?

Undertow 2.4.0 clears three CVEs and finally lands long-open HTTP/2 and timeout requests

Undertow's 2.4 line opened in May 2026 with a release that combines three CVE fixes with a backlog of feature requests, several of them years old judging by their issue numbers — in-flight request processing time tracking, comments in the predicate language, a configurable async context timeout replacing a hard-coded one, HTTP/2 GOAWAY connection management, a TLS protocol version exchange attribute, and a method to invalidate all cache paths. The two releases since have been small: a handful of Jiras in 2.4.1, and a 2.4.2 whose entire release note is the sentence that it was tagged.

Read the full Undertow trajectory →

Dapr vs Undertow: editorial side-by-side

D
Dapr
DEVOPS
5.0

Dapr is running three maintenance branches at once and shipping no new surface.

◆ Current state

Dapr is maintaining 1.16, 1.17 and 1.18 in parallel, with 1.18.3 currently working through release candidates. The recent window is entirely correctness and supply-chain work: workflow recovery, actor reminder registration, scheduler stream handling, an input-binding probe timeout, and Go and dependency bumps for reported CVEs. The same fixes appear repeatedly across branches as backports rather than as distinct changes.

◆ Where it's heading

The failure classes being closed cluster around durable execution — stalled workflows left unrecoverable, reminders that never registered, instance IDs reused while child workflows were still live. That is the part of Dapr customers run in production and cannot work around, and the maintenance effort is concentrated there rather than on new building blocks. Backporting the same fix to three branches signals a user base that upgrades slowly and is being supported where it sits.

◆ Prediction

1.18.3 should reach general availability once the release-candidate train stops accumulating backports, and the input-binding and workflow-recovery fixes will likely continue propagating to the older branches before any new capability appears.

U
Undertow
DEVOPS
0.0

Undertow 2.4.0 clears three CVEs and finally lands long-open HTTP/2 and timeout requests

◆ Current state

Undertow's 2.4 line opened in May 2026 with a release that combines three CVE fixes with a backlog of feature requests, several of them years old judging by their issue numbers — in-flight request processing time tracking, comments in the predicate language, a configurable async context timeout replacing a hard-coded one, HTTP/2 GOAWAY connection management, a TLS protocol version exchange attribute, and a method to invalidate all cache paths. The two releases since have been small: a handful of Jiras in 2.4.1, and a 2.4.2 whose entire release note is the sentence that it was tagged.

◆ Where it's heading

The 2.4.0 pattern — a long-deferred feature backlog shipping in the same release as security fixes — suggests features move when a release has to happen anyway rather than on their own schedule. What did ship points at operational control: timeouts that were hard-coded becoming configurable, connection lifecycle handling for HTTP/2, and attributes exposing TLS and timing detail to whatever sits above the server. Enabling test runs on JDK 25 in 2.4.1 is the only forward-looking item in the two follow-up releases.

◆ Prediction

With three entries and one substantive release among them, there is little to extrapolate from; the JDK 25 test enablement is the one thread that implies more work, pointing at runtime compatibility rather than features as the near-term focus.

Alternatives to Dapr and Undertow

Other DevOps products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Dapr or Undertow.

See all Dapr alternatives → · See all Undertow alternatives →

Recent activity from Dapr and Undertow

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 17h agoDapr1.18.3-rc.2: workflow recovery and placement backports
  2. 4d agoDapr1.17.12: Go 1.26.5 rebuild and a configurable input-binding probe
  3. 4d agoDapr1.16.18: input-binding probe fix backported
  4. 7d agoDapr1.18.3-rc.1: scheduler, workflow and dependency backports
  5. 20d agoDapr1.18.2: actor, SPIFFE, Kafka and sidecar fixes ship GA
  6. 24d agoDapr1.18.2-rc.4: workflow metrics and reminder-name recovery
  7. 1mo agoUndertow2.4.2.Final
  8. 2mo agoUndertowUndertow 2.4.1 makes the HTTP/1.1 reason-phrase optional
  9. 2mo agoUndertowUndertow 2.4.0 fixes three CVEs and adds HTTP/2 GOAWAY handling

Frequently asked questions

What is the difference between Dapr and Undertow?

They serve adjacent needs but don't currently overlap on shipped themes. Dapr is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is Dapr better than Undertow?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Dapr is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other DevOps products to evaluate alongside.

What are the best alternatives to Dapr?

Top Dapr alternatives in DevOps are ranked by recent ship velocity. Browse the "Dapr alternatives" section above for the current picks, or visit /alternatives/dapr for the full list with editorial commentary on each.

What are the best alternatives to Undertow?

Top Undertow alternatives in DevOps are ranked by recent ship velocity. Browse the "Undertow alternatives" section above for the current picks, or visit /alternatives/undertow for the full list with editorial commentary on each.