kron

Engine · Kotlin · engine: io_uring

kron — edixoi on Kotlin/Native: kron, the native port of the ioxide io_uring runtime, on its raw recv/send API and nothing above it. One reactor per core, each owning its ring and its share of the SO_REUSEPORT listeners; multishot accept and recv into provided buffer rings, the ring driven by hand from Kotlin over the kernel's own io_uring header through cinterop (no liburing, no JVM, no JIT: one native binary). Handlers are Kotlin suspend functions that the reactor resumes inline on the thread that took the completion, with no dispatcher and no thread pool. The HTTP/1.1 handling (request line, query string, case-insensitive headers, Content-Length and chunked bodies, keep-alive, pipelining, reads fragmented across recv boundaries) is edixoi's, ported to Kotlin — no framework, no router. One handler answers on both doors: plaintext on :8080, and TLS on :8081 for json-tls and the 8gbit echo, terminated with BoringSSL linked statically into the binary, with kernel TX offload where the kernel has the tls module and BoringSSL receive. The async profile's wait is an IORING_OP_TIMEOUT on the reactor's ring, so a held connection costs a kernel deadline rather than a thread. Companion to edixoi (C#) and edixoi-kt (the JVM port), which serve the same profiles.

Composite rank

Each profile of a family is worth 100 to the entry that leads it, and the composite is the sum over the family, less 2.5% for each of routing, middleware, request and response the entry does not do for you - its completeness factor, which the WebSocket and gRPC families do not carry. The field is this entry's own league: engines and reverse proxies are scored apart from frameworks. How it works.

Family	Rank	Composite
HTTP/1.1	4 of 43	6443

Every result

Alpha Round, 7 runs. Requests per second is the best of three; latency, CPU and memory come from that run.

Category	Profile	Conns	Req/sec	Avg	p99	CPU	Memory
Connection	Baseline	4,096	4,027,532	1.02ms	1.69ms	6420.7%	1.3GiB
Connection	Short-lived	4,096	2,690,422	1.39ms	2.06ms	5964.9%	1.4GiB
Concurrency	Async Delay	32,000	2,604,298	12.19ms	49.70ms	5839.3%	1.7GiB
Efficiency	Latency-10K	1,024	9,982	81.5us	115.0us	30.7%	1.3GiB
Efficiency	Latency-1M	1,024	997,515	97.7us	162.0us	2286.9%	1.3GiB
Workload	JSON TLS	4,096	1,802,467	1.32ms	33.17ms	5946.2%	1.5GiB
Workload	8Gbit	512	49,355	101.5us	121.0us	194.4%	3.4GiB

Compared with

The Kotlin entries around kron on the HTTP/1.1 composite, and the one leading them. The last column shows every profile side by side.

Entry	Composite	vs kron
ktron	7557	+17%	head to head
edixoi-kt	6803	+6%	head to head
genhttp-kt-netty	5539	-14%	head to head
ktor-tuned	3879	-40%	head to head

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Results updated 2026-10-28 · How the benchmark is run · The machine · Add or fix an entry