> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Replica Set Members (state), MongoDB

> Replica Set Members (state) for MongoDB deployments. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

**Card class:** [Non-Hero](/nerve-centre/overview#card-classes-explained)  •  **Category:** [Replication & Sharding](/nerve-centre/connectors#connectors-by-type)

## At a glance

> **Replica Set Members (state)** is a live table listing every member of the replica set with its hostname and current state string: `PRIMARY`, `SECONDARY`, `RECOVERING`, `STARTUP2`, `ARBITER`, `DOWN`, and so on. It is the single-glance answer to "is the cluster healthy and who is taking writes right now?" A well-formed set shows exactly one `PRIMARY` and the rest `SECONDARY` (plus any `ARBITER`); anything else (a missing primary, a member stuck in `RECOVERING`, or a node reporting `DOWN`) means replication or failover is mid-flight and writes may be blocked.

## What it tracks

The card is populated directly from `rs.status().members`, taking each member's `name` (host:port) and `stateStr` and rendering them as rows in real time. There is no aggregation window; it is the instantaneous topology of the set. The healthy shape is one and only one `PRIMARY` with all data-bearing peers in `SECONDARY`. Transient states are normal during maintenance: `STARTUP2` appears while a freshly added member performs its initial sync, and `RECOVERING` appears briefly during rollback or after a node rejoins. The states that warrant attention are a persistent `RECOVERING` (the member cannot catch up), `DOWN` or `(not reachable/healthy)` (the member is unreachable from the primary), or the absence of any `PRIMARY` (the set has lost quorum and is read-only until an election completes). This card carries no numeric alert of its own; its alerting partner is the [Replica Set Member Lag >10s or in RECOVERING State](/nerve-centre/kpi-cards/mongodb/replica-set-member-lag-10s-or-in-recovering-state) card.

## Reconciling against the source

Confirm against MongoDB directly by running `rs.status()` from `mongosh` on any member and reading the `members[].stateStr` field, or `rs.isMaster()` / `db.hello()` for the quick "who is primary" answer. On Atlas, the cluster topology view shows the same per-node roles and health. The Nerve Centre table mirrors `rs.status()` field-for-field, so any difference is a polling-interval timing gap during an in-progress election.

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### Tracked live in Vortex IQ Nerve Centre

*Replica Set Members (state)* is one of hundreds of KPI pulses Vortex IQ tracks across MongoDB and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

[Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.