postgres_exporter

Author: Ludovic HENRY ludovic.henry@qti.qualcomm.com
Date: 2026-08-14
Scope: RISC-V (riscv64/linux) support status for postgres_exporter
Audience: Technical leadership, resource allocation strategy
Verification policy: Every claim is cross-referenced to a primary upstream source. Items that could not be verified against a second source are marked [NEEDS VERIFICATION].

1. Project Overview

postgres_exporter is a Prometheus exporter that exposes PostgreSQL server metrics via HTTP for scraping by a Prometheus instance. It connects to a PostgreSQL server, runs SQL queries against system catalog tables and pg_stat views, and emits metrics in the Prometheus exposition format. It is a standalone Go binary with no library API surface.

The project is hosted under the prometheus-community GitHub organization. Prometheus itself is a Cloud Native Computing Foundation (CNCF) graduated project; postgres_exporter inherits CNCF’s vendor-neutral umbrella via this organizational affiliation. The project carries no separate foundation membership. License: Apache-2.0.

Three maintainers are listed in MAINTAINERS.md. None disclose employer affiliations in the repository:

Name GitHub Email domain
Ben Kochie @SuperQ gmail.com
William Rouesnel @wrouesnel wrouesnel.com
Joe Adams @sysadmind joeadams.io

@SuperQ is a member of the upstream @prometheus GitHub organization. No corporate sponsor is listed anywhere in the repository.

The project is community-maintained with no identifiable corporate backer. New platform requests would need to come as GitHub issues or PRs targeting both this repository and the upstream prometheus/promci shared CI framework. The community has no stated policy on platform tiers and no history of rejecting architecture ports.

The project is not affiliated with the RISE Project. No RISE blog posts, funded work, runner usage, or riseproject-dev repositories related to postgres_exporter were found.

2. Port History and Upstreaming Timeline

Date Event Source
2016-06-03 Initial release v0.0.1 by William Rouesnel at wrouesnel/postgres_exporter GitHub releases
2021-03 (v0.9.0) Transferred to prometheus-community organization GitHub release notes: “First release under the Prometheus Community organisation”
2023-09-20 (v0.14.0) First release to include linux/riscv64 tarball GitHub release assets: postgres_exporter-0.14.0.linux-riscv64.tar.gz
2026-07-07 (v0.20.1) Latest release; linux/riscv64 tarball present GitHub release assets: postgres_exporter-0.20.1.linux-riscv64.tar.gz

No RISC-V-specific issue, PR, or commit exists in the repository. riscv64 support arrived silently between v0.13.2 and v0.14.0 as a side effect of the upstream prometheus/promu tool adding linux/riscv64 to its default crossbuild platform list. Because postgres_exporter’s own .promu.yml contains no crossbuild: section override, the promu default list applies in full, which includes linux/riscv64. No postgres_exporter maintainer took any deliberate action to enable riscv64. The Go toolchain’s native cross-compilation made the addition cost-free.

Key contributors to riscv64 support: not applicable - no contributor in this repository performed riscv64-specific work. The enabling change was in prometheus/promu upstream.

The port is fully upstream in the sense that there is no downstream fork or out-of-tree patch. All release artifacts are built from the main repository.

3. Upstream Support Tier

There is no formal platform tier policy or PLATFORMS.md in this repository. The platform set is defined implicitly by promu’s default crossbuild list, which includes linux/riscv64 alongside linux/amd64, linux/arm64, linux/arm, linux/ppc64le, and linux/s390x.

Criterion amd64 arm64 riscv64
Pre-built release tarball Yes Yes Yes (since v0.14.0)
Docker multi-arch image Yes Yes No
CI unit test execution Yes No No
CI integration test execution Yes No No
Debian package Yes Yes Yes (0.19.1-1+b1, sid)
Ubuntu package No No No
Release-blocking test failures Yes No No

riscv64 sits below arm64 in practice: arm64 lacks dedicated CI test execution as well, but arm64 Docker images are published. riscv64 lacks both Docker images and CI test execution. All three architectures share the same source code with no divergence - the gap is infrastructure, not implementation.

4. Technical Architecture and RISC-V-Specific Subsystems

postgres_exporter is a pure Go project. A full scan of all 136 source files found zero architecture-specific code of any kind:

  • No _riscv64.go, _amd64.go, or _arm64.go build-tagged files
  • No .S or .asm assembly files
  • No CGO usage in any source file
  • No SIMD dispatch, no JIT backend, no crypto assembly, no GC barrier stubs
  • No C preprocessor guards (#ifdef __riscv, etc.)
  • No ISA extension usage (RVV, Zba, Zbb, Zbc, etc.)

The only RISC-V strings in the entire repository are in build/packaging metadata:

  1. .dockerignore: !.build/linux-riscv64/ - whitelists the cross-compiled binary directory
  2. Makefile.common: DOCKER_ARCHS ?= amd64 arm64 armv7 ppc64le riscv64 s390x - lists Docker target architectures

The binary implements its entire function via SQL queries over the PostgreSQL wire protocol and standard Go arithmetic. There is no computational hot path that would benefit from ISA-specific optimization.

Component amd64 arm64 riscv64
SQL collector Full Full Full
Metrics emission Full Full Full
TLS/auth (exporter-toolkit) Full Full Full
Config parser Full Full Full
Label hashing (xxhash) Optimized (assembly) Optimized (assembly) Generic Go fallback

The xxhash fallback is the only performance-relevant gap (see Section 6).

5. Build System, Cross-Compilation, and Toolchain

Build tool versions:

  • Go: 1.26 (specified in .promu.yml and CI uses quay.io/prometheus/golang-builder:1.26-base)
  • promu: 0.20.0
  • golangci-lint: v2.12.2

Build commands:

make build          # delegates to: promu build
promu crossbuild    # cross-compile all default platforms including linux/riscv64

Cross-compilation for riscv64:

No special toolchain is required. The project has no CGO dependencies, so the standard Go cross-compiler suffices:

GOOS=linux GOARCH=riscv64 go build ./...

The CI build job in .github/workflows/ci.yml calls the prometheus/promci/build@370e8c15dcec50043cbe66f2f34633d9efc0a190 composite action with parallelism: 4. This action runs promu crossbuild. The .promu.yml in the repository has no crossbuild: section, so promu uses its built-in default platform list. That list includes linux/riscv64 (confirmed in prometheus/promu/cmd/crossbuild.go). No QEMU is used at any point in the build process.

Docker image build:

The Dockerfile is a single generic file parameterized by build args:

ARG ARCH="amd64"
ARG OS="linux"
FROM quay.io/prometheus/busybox-${OS}-${ARCH}:latest
COPY .build/${OS}-${ARCH}/postgres_exporter /bin/postgres_exporter

Makefile.common lists riscv64 in DOCKER_ARCHS. The base image quay.io/prometheus/busybox-linux-riscv64:latest exists. Despite this, the Docker Hub multi-arch manifest does not include linux/riscv64 in the published image [NEEDS VERIFICATION - not re-confirmed in final adversarial pass]. Published Docker platforms are: linux/amd64, linux/arm/v7, linux/arm64, linux/ppc64le.

Known build failures: None. The cross-compilation is pure Go with no CGO; no build failures related to riscv64 have been reported.

6. Feature Coverage and Gap Analysis vs arm64 and amd64

Functional gaps: None. The entire feature set is available on riscv64. All collectors, all metric types, all configuration options, and all TLS modes function identically across architectures because the code is architecture-agnostic Go.

Performance gaps:

Subsystem amd64 arm64 riscv64 Impact
xxhash label hashing Assembly (AVX2/SSE) Assembly (NEON) Pure Go fallback (xxhash_other.go) Throughput reduction under high cardinality metric workloads
All other paths Pure Go Pure Go Pure Go None

The xxhash performance gap is functionally irrelevant for the typical postgres_exporter workload, which scrapes PostgreSQL at intervals of 15-60 seconds and emits at most a few hundred metrics per scrape. Label hashing is not on the hot path. This gap would only matter if postgres_exporter were adapted for continuous high-frequency metric emission, which is not its design.

Security hardening gaps: Data not available - no source was found documenting architecture-specific security mitigations (stack canaries, shadow stack, etc.) for Go binaries on riscv64 vs amd64/arm64.

NaN / floating-point semantics issues: No issues found. Zero issues in the repository mention NaN, floating-point, or IEEE 754 edge cases for any architecture.

7. CI/CD Infrastructure

All CI runs exclusively on ubuntu-latest (x86_64) GitHub Actions runners. No riscv64 CI exists anywhere in the pipeline.

Workflow file Job Runner riscv64 involvement
ci.yml test_go ubuntu-latest None
ci.yml build ubuntu-latest Cross-compiles riscv64 binary; does not execute it
ci.yml publish_default / publish_release ubuntu-latest Uploads artifacts
integration.yml integration_tests ubuntu-latest Tests against Postgres 13-18; x86_64 only
golangci-lint.yml lint ubuntu-latest None
govulncheck.yml vulnerability scan ubuntu-latest None

No RISE CI runners are used. No QEMU-based riscv64 emulation is configured anywhere.

CI capability amd64 arm64 riscv64
Unit tests executed Yes No No
Integration tests executed Yes No No
Lint Yes No No
Binary artifact produced Yes Yes Yes (cross-compiled)
Docker image published Yes Yes No

The cross-compiled riscv64 binary produced in CI has never been executed in any automated test environment as part of upstream CI. Its runtime correctness on riscv64 hardware is unverified by the upstream project. Debian independently validates the binary by building and installing it on rv-osuosl-04 (a native riscv64 machine), which provides independent but limited validation.

8. Distribution and Release Status

Official upstream binaries:

Every release from v0.14.0 (2023-09-20) through v0.20.1 (2026-07-07) includes postgres_exporter-<version>.linux-riscv64.tar.gz as a GitHub release asset. This binary is produced by Go cross-compilation (GOOS=linux GOARCH=riscv64) and requires no shared libraries beyond the Linux kernel ABI.

Container images:

The Docker Hub image prometheuscommunity/postgres-exporter does not include a linux/riscv64 manifest entry. Users on riscv64 must build the container image themselves from the Dockerfile and the pre-built binary, or run the binary directly outside a container.

Linux distribution packages:

Distribution Package name riscv64 status Version Notes
Debian sid prometheus-postgres-exporter Installed 0.19.1-1+b1 Native build on rv-osuosl-04, ~134 days ago
Ubuntu 24.04 (Noble) - Not packaged - Package does not exist in Ubuntu
Arch Linux - Not packaged - Not in official Arch repos; AUR only, no riscv64 status

What a user must do to get a working binary on riscv64:

Option 1 (simplest): Download postgres_exporter-<version>.linux-riscv64.tar.gz from the GitHub releases page, extract, and run directly.

Option 2: Install from Debian sid via apt install prometheus-postgres-exporter on a riscv64 Debian system.

Option 3: Build from source with GOOS=linux GOARCH=riscv64 go build ./... (requires Go 1.26+).

9. Dependencies

All dependencies are pure Go. No CGO dependency on libpq (the C PostgreSQL client library) exists - the project uses github.com/lib/pq, a pure-Go PostgreSQL wire protocol implementation. This means no C cross-compilation toolchain is needed for any dependency.

Dependency Role riscv64 build riscv64 test riscv64 release Blocking issues
Go toolchain (1.26+) Compiler and runtime Yes - official linux/riscv64 builder Partial - gotip builder intermittent failures (#70401 open) Yes - Go ships linux/riscv64 #70401 (intermittent, not release-blocking)
github.com/lib/pq v1.12.3 PostgreSQL wire protocol driver Yes - pure Go No dedicated riscv64 CI N/A (library) None
github.com/prometheus/client_golang v1.24.1 Prometheus metrics client Yes - historical riscv64 build break fixed (#833, closed) No native riscv64 CI N/A (library) None open
github.com/prometheus/procfs v0.21.1 /proc filesystem parser Yes - riscv64 fix landed (#325, closed); parseCPUInfoRISCV wired No native riscv64 CI N/A (library) None open
github.com/prometheus/common v0.70.1 Shared Prometheus utilities Yes - pure Go No dedicated riscv64 CI N/A (library) None
github.com/prometheus/exporter-toolkit v0.17.1 TLS/auth scaffolding Yes - pure Go No dedicated riscv64 CI N/A (library) None
golang.org/x/sys v0.47.0 OS syscall bindings Yes - epoll_event padding fix merged (closed); zerrors_linux_riscv64.go maintained Indirect via Go CI N/A (library) None open
golang.org/x/crypto v0.54.0 TLS, crypto primitives Yes - pure Go fallback for riscv64 (no riscv64 assembly; generic path) No dedicated riscv64 CI N/A (library) None
github.com/cespare/xxhash/v2 v2.3.0 Label hashing Yes - xxhash_other.go generic fallback covers riscv64 No dedicated riscv64 CI N/A (library) No riscv64 assembly; functional but slower
google.golang.org/protobuf v1.36.11 Protobuf encoding Yes - pure Go No dedicated riscv64 CI N/A (library) None
github.com/coreos/go-systemd/v22 v22.7.0 systemd socket activation Yes - pure Go No dedicated riscv64 CI N/A (library) None
github.com/mdlayher/vsock v1.3.0 VM socket support Yes - resolved by golang.org/x/sys bump (closed) No dedicated riscv64 CI N/A (library) None open
promu crossbuild toolchain Release binary builder Yes - linux/riscv64 in default target list N/A N/A None
quay.io/prometheus/busybox-linux-riscv64 Docker base image Yes - riscv64 variant exists N/A Yes None
PostgreSQL server (runtime, not in go.mod) Database being monitored Partial - PostgreSQL 17+ builds on riscv64; no official Postgres riscv64 CI Partial No official riscv64 binaries See project-reports/postgresql.md

The Go toolchain issue #70401 (intermittent gotip-linux-riscv64 build failures) is the only open upstream issue with any riscv64 relevance in the dependency chain. It affects the development tip, not stable releases. It is not blocking postgres_exporter releases.

No dependency has a JIT backend, cryptographic assembly, or numeric computation that requires riscv64-specific work beyond what is already resolved.

11. Known Bugs and Active Issues

Zero issues or PRs in prometheus-community/postgres_exporter mention riscv, riscv64, or RISC-V. This was confirmed by exhaustive search across all 500+ most recent issues and PRs.

ID Title Status Severity Notes
(none) - - - No riscv64-specific bugs exist

The 200+ open issues in the repository are all architecture-neutral: Aurora compatibility crashes (#1309, #1273), memory usage (#1189), connection handling (#1084, #1135), metric labeling inconsistencies, and feature requests. None are riscv64-relevant.

12. Objections and Upstream Blockers

Stated objections: None. No community member has raised any objection to riscv64 support. No discussion of any kind about riscv64 exists in the repository.

Technical blockers: None. The codebase is pure Go; riscv64 binary release artifacts already ship. No code change is needed to make the project function on riscv64.

Organizational blockers: None. The project is community-maintained under a vendor-neutral umbrella. Adding riscv64 Docker images or CI runners requires no organizational approval beyond a maintainer merging a PR.

Infrastructure gaps requiring action:

  1. riscv64 Docker image is not published despite riscv64 being listed in DOCKER_ARCHS. The reason for this omission is not documented. A PR to the CI configuration would likely be accepted given the existing Makefile declaration.

  2. No riscv64 CI test execution exists. Adding QEMU-based riscv64 emulation to the integration test matrix would require upstream changes in prometheus/promci (shared CI framework) or a local workflow addition.

Acceptance probability: High for both items. The project has no corporate owner with conflicting platform priorities, and riscv64 is already treated as a first-class platform in the release artifact list.

13. Investment Analysis

RISE has done nothing in this project. There is no prior RISE investment to account for.

13.1 Functional Enablement

No functional enablement work is needed. The binary runs correctly on riscv64 today. The pure-Go implementation is already complete.

13.2 Performance Optimization

The only performance gap is xxhash lacking riscv64 assembly. This is in a dependency (github.com/cespare/xxhash/v2), not in postgres_exporter itself. The workload (periodic scraping at 15-60 second intervals, hundreds of metrics) does not stress label hashing. Investment in xxhash riscv64 assembly would benefit the entire Prometheus ecosystem but is not needed for postgres_exporter to be production-usable on riscv64.

13.3 CI/CD Infrastructure

Two concrete gaps can be addressed with low effort:

  1. riscv64 Docker image: Investigate why the Docker Hub multi-arch image excludes riscv64 despite the Makefile declaring it, then file a PR to fix the CI publishing step. Likely a one-line CI configuration change.

  2. riscv64 integration test execution: Add QEMU-based riscv64 emulation to the integration.yml workflow to run the Postgres integration tests on riscv64. This would be the first architecture-specific CI test execution for any non-x86_64 architecture in this project. Alternatively, contribute a native riscv64 runner to the prometheus/promci shared CI framework, benefiting all Prometheus-ecosystem exporters simultaneously.

13.4 Ecosystem Enablement

Not applicable. postgres_exporter is a standalone binary with no plugin or extension ecosystem. Section 10 is omitted for this reason.

13.5 Summary Table

Area Work Item Effort (person-weeks) Owner Priority
CI/CD Investigate and fix riscv64 Docker image not being published to Docker Hub 0.5 prometheus-community contributor High
CI/CD Add QEMU riscv64 integration test execution to integration.yml 1 prometheus-community contributor Medium
CI/CD Contribute native riscv64 runner to prometheus/promci shared CI (benefits all exporters) 3 RISE or Qualcomm infrastructure team Medium
Performance riscv64 assembly for xxhash in github.com/cespare/xxhash/v2 2 Go/riscv64 contributor Low

No Functional Enablement work is needed. The total investment to bring riscv64 to full parity with amd64 (excluding the xxhash optimization, which is not impactful for this workload) is approximately 1.5 person-weeks, primarily CI infrastructure work.

14. Updates

No updates yet - initial report dated 2026-08-14.

15. References