[GH-ISSUE #49] Single bridge network caps concurrent terminals at ~1024 (exchange full) — no sharding, no early warning #21

New issue

Closed

opened 2026-10-18 21:13:27 +00:00 by bsakaguchi · 2 comments

bsakaguchi commented

2026-10-18 21:13:27 +00:00

Owner

Originally created by @Classic298 on GitHub (Jul 20, 2026).
Original GitHub issue: https://github.com/open-webui/terminals/issues/49

With the Docker backend, all user terminals attach to one bridge network (TERMINALS_NETWORK). A Linux bridge supports at most 1024 ports (BR_PORT_BITS=10, kernel compile-time constant). At ~1024 concurrently-running containers, provisioning fails hard:


failed to set up container networking: failed to create endpoint … on network <net>:
adding interface vethXXXX to bridge br-… failed: exchange full

New terminals can't start, and the failure surfaces as an opaque Docker error rather than a clear "network capacity reached" from the orchestrator.

Impact: any deployment expecting >~1000 simultaneous sessions hits an undocumented hard wall. (We reached it via a separate reaper bug leaking containers, but a legitimately busy install would hit it too.)

Requests:

Document the ~1024-per-bridge ceiling for the Docker backend in the scaling docs.
Fail clearly — detect the bridge is at/near capacity and return an explicit error/metric instead of the raw exchange full.
Support scaling past it, e.g. shard across multiple bridge networks (round-robin users), or document/support an ipvlan/macvlan network driver that isn't bound by the bridge port cap.

Environment: Docker backend, single TERMINALS_NETWORK bridge, Linux host.

Originally created by @Classic298 on GitHub (Jul 20, 2026). Original GitHub issue: https://github.com/open-webui/terminals/issues/49 With the Docker backend, all user terminals attach to one bridge network (TERMINALS_NETWORK). A Linux bridge supports at most 1024 ports (BR_PORT_BITS=10, kernel compile-time constant). At ~1024 concurrently-running containers, provisioning fails hard: ``` failed to set up container networking: failed to create endpoint … on network <net>: adding interface vethXXXX to bridge br-… failed: exchange full ``` New terminals can't start, and the failure surfaces as an opaque Docker error rather than a clear "network capacity reached" from the orchestrator. Impact: any deployment expecting >~1000 simultaneous sessions hits an undocumented hard wall. (We reached it via a separate reaper bug leaking containers, but a legitimately busy install would hit it too.) Requests: 1. Document the ~1024-per-bridge ceiling for the Docker backend in the scaling docs. 2. Fail clearly — detect the bridge is at/near capacity and return an explicit error/metric instead of the raw exchange full. 3. Support scaling past it, e.g. shard across multiple bridge networks (round-robin users), or document/support an ipvlan/macvlan network driver that isn't bound by the bridge port cap. Environment: Docker backend, single TERMINALS_NETWORK bridge, Linux host.

bsakaguchi closed this issue

2026-10-18 21:13:28 +00:00

bsakaguchi commented

2026-10-18 21:13:29 +00:00

Author

Owner

@owui-terminator[bot] commented on GitHub (Jul 20, 2026):

⚠️ Missing Issue Title Prefix

@Classic298, your issue title is missing a categorising prefix (e.g. bug:, feat:, docs:).

Please update the title to lead with one of:

bug: bug report or error
feat: feature request or enhancement
docs: documentation issue
question: usage question
help: support request

Example: bug: Login fails when the password contains special characters

@owui-terminator[bot] commented on GitHub (Jul 20, 2026): # ⚠️ Missing Issue Title Prefix @Classic298, your issue title is missing a categorising prefix (e.g. `bug:`, `feat:`, `docs:`). Please update the title to lead with one of: - **bug**: bug report or error - **feat**: feature request or enhancement - **docs**: documentation issue - **question**: usage question - **help**: support request Example: `bug: Login fails when the password contains special characters`

bsakaguchi commented

2026-10-18 21:13:29 +00:00

Author

Owner

@owui-terminator[bot] commented on GitHub (Jul 20, 2026):

🔍 Related Issues Found

I found some existing issues that might be related. Please check if any of these are duplicates or contain helpful solutions:

🟣 #25 How to specify custom network?
This issue is about configuring which Docker network terminals uses for spawned containers. It is directly related to the new report’s concern about the single bridge network design and the need to shard or otherwise change network placement to scale.
by arp-mbender

💡 If your issue is a duplicate, please close it and add any additional details to the existing issue instead.

This comment was generated automatically. React with 👍 if helpful, 👎 if not.

@owui-terminator[bot] commented on GitHub (Jul 20, 2026):  🔍 **Related Issues Found** I found some existing issues that might be related. Please check if any of these are duplicates or contain helpful solutions: 1. 🟣 [#25](https://github.com/open-webui/terminals/issues/25) **How to specify custom network?** *This issue is about configuring which Docker network terminals uses for spawned containers. It is directly related to the new report’s concern about the single bridge network design and the need to shard or otherwise change network placement to scale.* *by arp-mbender* --- 💡 If your issue is a duplicate, please close it and add any additional details to the existing issue instead. *This comment was generated automatically.* React with 👍 if helpful, 👎 if not.

bsakaguchi referenced this issue

2026-10-18 21:13:49 +00:00

[PR #26] [CLOSED] feat: make log level configurable #51