fix(native-sidecar): stop retaining disposed VM filesystem snapshots by eersnington · Pull Request #2104 · rivet-dev/agentos

eersnington · 2026-11-12T22:13:54Z

On dispose, the sidecar snapshots the VM's root filesystem and hands it to the stdio bridge. LocalBridge stored each snapshot in a map keyed by VM id and never removed it.
VM ids come from a per-process counter and are never reused, so no snapshot was ever read back. Every disposed VM's files stayed in sidecar memory until the sidecar exited.
LocalBridge now discards snapshots. Only test bridges implement load/flush with real storage.
Adds a Linux nightly test that disposes VMs on a real sidecar and checks sidecar memory stays flat.

Sidecar, 150 create + 2 MB write + dispose cycles	Memory (PSS)
main	33 → 985 MiB, ~6.3 MiB per cycle
this PR	33 → 183 MiB, flat after warm-up

- The stdio sidecar bridge stored every disposed VM's root filesystem snapshot keyed by VM id. - VM ids are never reused in a sidecar process, so the snapshots were never read and each create/dispose cycle leaked the VM's files (~5.6 MiB per cycle in the repro). - Add a Linux nightly test that checks sidecar memory stays flat across VM create/write/dispose cycles.

github-actions · 2026-11-12T22:29:13Z

📟 Pip-Boy · `b027ec3`

📦 Packages · fresh `npm install` resolve, no lockfile · this PR vs base

🔴 Registry drift: @rivet-dev/agentos-core@latest, @rivet-dev/agentos-posix@latest, @rivet-dev/agentos-runtime-core@latest, @rivet-dev/agentos-sandbox@latest is already over budget for anyone installing it today. This PR didn't cause it.

package (linux-x64-gnu)	`@latest`	base	this PR	Δ vs base	packages
`@rivet-dev/agentos-core`	776.0 MB	776.0 MB	776.0 MB	0 · over 550.0 MB budget	10 (0)
`@rivet-dev/agentos-posix`	703.7 MB	703.7 MB	703.7 MB	0 · over 305.0 MB budget	7 (0)
`@rivet-dev/agentos-runtime-core`	703.7 MB	703.7 MB	703.7 MB	0 · over 305.0 MB budget	6 (0)
`@rivet-dev/agentos-sandbox`	813.6 MB	813.7 MB	813.7 MB	0 · over 600.0 MB budget	85 (0)

`@rivet-dev/agentos-core` details

platform	base	this PR
linux-x64-gnu	776.0 MB	776.0 MB
linux-arm64-gnu	779.3 MB	779.3 MB
darwin-arm64	452.2 MB	452.2 MB
darwin-x64	453.0 MB	453.0 MB
win32-x64	182.3 MB	182.3 MB

Largest dependencies

package	size	via
`@rivet-dev/agentos-runtime-sidecar-linux-x64-gnu@0.4.7`	593.7 MB	`@rivet-dev/agentos-core › @rivet-dev/agentos-runtime-sidecar › @rivet-dev/agentos-runtime-sidecar-linux-x64-gnu`
`@rivet-dev/agentos-runtime-core`	103.9 MB	`@rivet-dev/agentos-core › @rivet-dev/agentos-runtime-core`
`zod@4.6.7`	5.9 MB	`@rivet-dev/agentos-core › zod`
`@xterm/headless@6.0.0`	1.9 MB	`@rivet-dev/agentos-core › @xterm/headless`
`zod-to-json-schema@3.25.2`	214.1 KB	`@rivet-dev/agentos-core › @rivet-dev/agentos-runtime-core › zod-to-json-schema`

`@rivet-dev/agentos-posix` details

platform	base	this PR
linux-x64-gnu	703.7 MB	703.7 MB
linux-arm64-gnu	707.1 MB	707.1 MB
darwin-arm64	379.9 MB	379.9 MB
darwin-x64	380.7 MB	380.7 MB
win32-x64	110.0 MB	110.0 MB

Largest dependencies

package	size	via
`@rivet-dev/agentos-runtime-sidecar-linux-x64-gnu@0.4.7`	593.7 MB	`@rivet-dev/agentos-posix › @rivet-dev/agentos-runtime-core › @rivet-dev/agentos-runtime-sidecar › @rivet-dev/agentos-runtime-sidecar-linux-x64-gnu`
`@rivet-dev/agentos-runtime-core`	103.9 MB	`@rivet-dev/agentos-posix › @rivet-dev/agentos-runtime-core`
`zod@4.6.7`	5.9 MB	`@rivet-dev/agentos-posix › @rivet-dev/agentos-runtime-core › zod`
`zod-to-json-schema@3.25.2`	214.1 KB	`@rivet-dev/agentos-posix › @rivet-dev/agentos-runtime-core › zod-to-json-schema`
`@bare-ts/lib@0.4.1`	82.2 KB	`@rivet-dev/agentos-posix › @rivet-dev/agentos-runtime-core › @bare-ts/lib`

`@rivet-dev/agentos-runtime-core` details

platform	base	this PR
linux-x64-gnu	703.7 MB	703.7 MB
linux-arm64-gnu	707.1 MB	707.1 MB
darwin-arm64	379.9 MB	379.9 MB
darwin-x64	380.7 MB	380.7 MB
win32-x64	110.0 MB	110.0 MB

Largest dependencies

package	size	via
`@rivet-dev/agentos-runtime-sidecar-linux-x64-gnu@0.4.7`	593.7 MB	`@rivet-dev/agentos-runtime-core › @rivet-dev/agentos-runtime-sidecar › @rivet-dev/agentos-runtime-sidecar-linux-x64-gnu`
`zod@4.6.7`	5.9 MB	`@rivet-dev/agentos-runtime-core › zod`
`zod-to-json-schema@3.25.2`	214.1 KB	`@rivet-dev/agentos-runtime-core › zod-to-json-schema`
`@bare-ts/lib@0.4.1`	82.2 KB	`@rivet-dev/agentos-runtime-core › @bare-ts/lib`
`@rivet-dev/agentos-runtime-sidecar@0.4.7`	6.5 KB	`@rivet-dev/agentos-runtime-core › @rivet-dev/agentos-runtime-sidecar`

`@rivet-dev/agentos-sandbox` details

platform	base	this PR
linux-x64-gnu	813.7 MB	813.7 MB
linux-arm64-gnu	818.1 MB	818.1 MB
darwin-arm64	483.6 MB	483.6 MB
darwin-x64	485.1 MB	485.1 MB
win32-x64	226.9 MB	226.9 MB

Largest dependencies

package	size	via
`@rivet-dev/agentos-runtime-sidecar-linux-x64-gnu@0.4.7`	593.7 MB	`@rivet-dev/agentos-sandbox › @rivet-dev/agentos-core › @rivet-dev/agentos-runtime-sidecar › @rivet-dev/agentos-runtime-sidecar-linux-x64-gnu`
`@rivet-dev/agentos-runtime-core`	103.9 MB	`@rivet-dev/agentos-sandbox › @rivet-dev/agentos-core › @rivet-dev/agentos-runtime-core`
`@rivet-dev/agentos-core`	70.3 MB	`@rivet-dev/agentos-sandbox › @rivet-dev/agentos-core`
`@sandbox-agent/cli-linux-x64@0.4.2`	23.5 MB	`@rivet-dev/agentos-sandbox › sandbox-agent › @sandbox-agent/cli › @sandbox-agent/cli-linux-x64`
`zod@4.6.7`	5.9 MB	`@rivet-dev/agentos-sandbox › @rivet-dev/agentos-core › zod`

Floating 0.x ranges (resolve above their floor today)

range	declared by	resolves to	subtree
`@grpc/proto-loader@^0.8.0`	`@grpc/grpc-js@1.14.7`	`0.8.1`	6.5 MB
`@grpc/proto-loader@^0.7.13`	`dockerode@4.0.12`	`0.7.15`	6.5 MB
`tweetnacl@^0.14.3`	`bcrypt-pbkdf@1.0.2`	`0.14.5`	170.0 KB
`mkdirp-classic@^0.5.2`	`tar-fs@2.1.5`	`0.5.3`	4.4 KB

All 6 packages · linux-x64-gnu

package (linux-x64-gnu)	`@latest`	base	this PR	Δ vs base	packages
`@rivet-dev/agentos-core`	776.0 MB	776.0 MB	776.0 MB	0 · over 550.0 MB budget	10 (0)
`@rivet-dev/agentos-node-pty`	7.6 KB	18.0 KB	18.0 KB	0	1 (0)
`@rivet-dev/agentos-posix`	703.7 MB	703.7 MB	703.7 MB	0 · over 305.0 MB budget	7 (0)
`@rivet-dev/agentos-runtime-core`	703.7 MB	703.7 MB	703.7 MB	0 · over 305.0 MB budget	6 (0)
`@rivet-dev/agentos-sandbox`	813.6 MB	813.7 MB	813.7 MB	0 · over 600.0 MB budget	85 (0)
`@rivet-dev/agentos-toolchain`	130.8 KB	141.2 KB	141.2 KB	0	2 (0)

🧹 Rust dependencies · `cargo deny` + `cargo shear`

check	new in this PR	existing on base
advisories	✅ 0	45
licenses	✅ 0	0
sources	✅ 0	0
bans	✅ 0	0
unused	✅ 0	16

🦀 Binaries · publish Dockerfiles, `--release`

Base: main@a714718, the merge base.

artifact	npm `@latest`	base	this PR	Δ vs base
`agentos-native-sidecar linux-x64-gnu`	593.7 MB	144.0 MB	144.0 MB	+1.3 KB (+0.0%)

⏱ Timing

job	wall time	slowest step
`changes`	26s	`checkout` · 21s
`zizmor`	10s	`checkout` · 3s
`footprint`	1m45s	`Pack this commit` · 34s
`hygiene`	58s	`checkout` · 21s
`native · linux-x64-gnu`	14m24s	`Build with the publish Dockerfile` · 14m03s
⏭ `self-test`	—	skipped
`report`	18s	`Write the comment and run summary` · 5s

🔭 Full CI trace for this commit

One OpenTelemetry trace of CI and Pip-Boy for b027ec3: every job and step, with the sizes above attached. Run after CI finishes.

pnpm install --frozen-lockfile --filter 'pipboy...'
pnpm --filter pipboy pipboy trace --sha b027ec31638ae0f721508250ff691a941a996ad4

Add --otlp <url> to send it to any OTLP/HTTP collector.

Agent instruction: From a rivet-dev/agentos checkout, run the commands above, then read the trace file the last command prints. List the slowest jobs and steps and explain where CI time went.

eersnington merged commit 082b80a into main Nov 12, 2026
14 of 15 checks passed

eersnington deleted the fix/vm-dispose-snapshot-leak branch November 12, 2026 22:36

Navigation Menu

Repository navigation

fix(native-sidecar): stop retaining disposed VM filesystem snapshots - #2104

fix(native-sidecar): stop retaining disposed VM filesystem snapshots#2104
eersnington merged 1 commit into
mainfrom
fix/vm-dispose-snapshot-leak

eersnington commented Nov 12, 2026

Uh oh!

github-actions Bot commented Nov 12, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

eersnington commented Nov 12, 2026

Uh oh!

github-actions Bot commented Nov 12, 2026

📟 Pip-Boy · b027ec3

📦 Packages · fresh npm install resolve, no lockfile · this PR vs base

🧹 Rust dependencies · cargo deny + cargo shear

🦀 Binaries · publish Dockerfiles, --release

⏱ Timing

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

📟 Pip-Boy · `b027ec3`

📦 Packages · fresh `npm install` resolve, no lockfile · this PR vs base

🧹 Rust dependencies · `cargo deny` + `cargo shear`

🦀 Binaries · publish Dockerfiles, `--release`