Network Connection Quota Management

Parent: Atlas Triage Workflows · Published reference · snapshot 2026-10-15

Depth-first rabbithole dossier for Network Connection Quota Management; source-anchored research pack.

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Problems, failure modes and limitations

[low] If connection spikes occur with traffic increases, set minPoolSize closer to maxPoolSize; if spikes occur during deployments or network disruptions, set maxPoolSize to limit total connections per application instance. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]
[low] To confirm connection storms or limit issues, run the serverStatus command and check for sudden increases in connections.current, connections.active, connections.totalCreated, or metrics.network.totalIngressTLSHandshakeTimeMillis. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]
[low] An M10 Atlas Core cluster has three nodes with a 1500 connection limit per node, with Atlas reserving 10 connections per node for internal services. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] If the read preference is set to secondary, Atlas can read from the two secondary nodes for a combined 2980 connection limit. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] When a node reaches its connection rate limit, Atlas queues new connection attempts and drops some connections if the overload is sustained. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] Each MongoDB Atlas cluster tier enforces a maximum number of concurrent incoming connections per node, and exceeding this limit may result in connection refused errors. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]
[low] If the connection count is at or near the cluster tier limit, consider upgrading to a higher cluster tier to increase the per-node connection limit. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]

Facts and statements

[low] Connection rate limiting is active on M10 and M20 clusters running specific MongoDB versions. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/atlas/intelligent-workload-management.md [source]
[low] During connection storms, Atlas admits new client connections at a safe rate and rejects excess requests while preserving existing connections. Sources: https://www.mongodb.com/docs/atlas/intelligent-workload-management.md [source]
[low] Atlas applies connection rate limits to protect cluster availability, restricting the number of new incoming connections each node can accept per second. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] Connection rate limiting is always on for M10 and M20 cluster tiers, and for M30+ tiers running MongoDB 9.0 or later, but always off for M30+ tiers running earlier MongoDB versions. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] Atlas connection limits apply per node, or per mongos router for sharded clusters, and do not include connections from Atlas internal services. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] The net.maxIncomingConnections setting caps the total number of incoming connections a node holds open at one time. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] The Real-Time Performance Panel (RTPP) in the Atlas UI provides insights into network traffic, database operations, and hardware statistics at one-second granularity, but is not available via the Atlas Administration API. Sources: https://www.mongodb.com/docs/atlas/architecture/current/monitoring-alerts.md [source]
[low] Atlas scales clusters based on memory and compute use, not on connections. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] If nearing the maximum connection count, options to redistribute connections or increase limits include enabling cluster auto-scaling, connection pooling, tuning the application, or scaling the cluster tier. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md [source]
[low] If high connections.active values and elevated query latency are observed, set minPoolSize closer to maxPoolSize in the driver connection string. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]
[low] On sharded clusters, each mongos router maintains connection pools on each shard, which can be limited by setting the taskExecutorPoolSize parameter and controlled by ShardingTaskExecutorPoolMinSize and ShardingTaskExecutorPoolMaxSize. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]
[low] Increases in metrics.commands.<command>.failed can also indicate connection or performance issues. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md [source]

Related concepts

Connection — is a part of Network Connection Quota Management
Network — is a part of Network Connection Quota Management

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