runtime-configuration

Documentation for changing the members of an etcd cluster while it is running. etcd is a distributed data store that requires a working majority of members to process membership changes.

In plain words
What is it for?
Use it when adding or removing cluster members, cycling machines during maintenance, changing cluster size, replacing failed machines, or recovering after a majority failure.
Why use it?
It explains how to handle upgrades, machine replacement, cluster resizing, and recovery without losing the cluster’s ability to make progress.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/openshift-eng/two-node-toolbox/runtime-configuration
Clone the repo
git clone --depth 1 https://github.com/openshift-eng/two-node-toolbox

Made for: Claude Code.

Per session 7 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,430 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00007 $0.03430
Opus 5 $0.00003 $0.01715
Sonnet 5 $0.00001 $0.00686
Haiku 4.5 $0.00001 $0.00343

Measured yesterday against content hash 5c51c05c026e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

runtime-configuration scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/etcd/etcd-ops-guide/runtime-configuration.md · 253 lines

How it starts

The opening of the file, as written. The whole thing — 253 lines — stays where its author put it; the contents beside it link to each section on GitHub.

etcd comes with support for incremental runtime reconfiguration, which allows users to update the membership of the cluster at run time.

Reconfiguration requests can only be processed when a majority of cluster members are functioning. It is highly recommended to always have a cluster size greater than two in production. It is unsafe to remove a member from a two member cluster. The majority of a two member cluster is also two. If there is a failure during the removal process, the cluster might not be able to make progress and need to [restart from majority failure][majority failure].

To better understand the design behind runtime reconfiguration, please read [the runtime reconfiguration document][runtime-reconf].

Reconfiguration use cases

This section will walk through some common reasons for reconfiguring a cluster. Most of these reasons just involve combinations of adding or removing a member, which are explained below under [Cluster Reconfiguration Operations][cluster-reconf].

Cycle or upgrade multiple machines

If multiple cluster members need to move due to planned maintenance (hardware upgrades, network downtime, etc.), it is recommended to modify members one at a time.

It is safe to remove the leader, however there is a brief period of downtime while the election process takes place. If the cluster holds more than 50MB of v2 data, it is recommended to [migrate the member's data directory][member migration].

Change the cluster size

Increasing the cluster size can enhance [failure tolerance][fault tolerance table] and provide better read performance. Since clients can read from any member, increasing the number of members increases the overall serialized read throughput.

Decreasing the cluster size can improve the write performance of a cluster, with a trade-off of decreased resilience. Writes into the cluster are replicated to a majority of members of the cluster before considered committed. Decreasing the cluster size lowers the majority, and each write is committed more quickly.

Read the full file on GitHub · 253 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 253 lines · 7 tokens per session scan A 5c51c05c026e

Subscribe to this mod's changes

runtime-configuration is a command published in the GitHub repository openshift-eng/two-node-toolbox (5 stars, last pushed 28d ago), licensed Apache-2.0. It adds 7 tokens to every session and 3,430 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.