# Error Codes and Troubleshooting Operational Runbook > Depth-first rabbithole dossier for Error Codes and Troubleshooting Operational Runbook; source-anchored research pack. Parent: [Error Codes and Troubleshooting](https://llms-explorer.com/tree/error-codes-and-troubleshooting/) · 5 facets · 56 facts · page: https://llms-explorer.com/tree/error-codes-and-troubleshooting-operational-runbook/ ## Structure and components - [low] MongoDB logs `REJECTED` component messages only if the verbosity level is at least `2`, while operations returning errors are included in system logs only if the verbosity level is at least `1`, with a default verbosity of `0`. Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` ## How it works - [low] Exceeding the recommended maximum number of collections and indexes can cause database operations to run more slowly. Separately, for MongoDB Search indexes, smaller cluster tiers like M10 can experience performance degradation or out-of-memory errors as index count increases. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Cluster connection limits are enforced for AWS only when connecting over private link for supported versions: 8.1 and v8.1.0+, 8.0 and v8.0.10+, and 7.0 and v7.0.22+. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] By default, when a rollback occurs, MongoDB writes the rollback data to BSON files located in a `/rollback/` directory, and you can use `bsondump` to read the contents. Sources: https://www.mongodb.com/docs/manual/core/replica-set-rollbacks.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] When the cache reaches critical thresholds, the server uses application threads to evict pages, reducing threads available for replication, and if Result > 0 and increasing, the database is under cache pressure, increasing replication lag. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replication-lag.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Collection scans can evict data and index pages from the working set, increasing replication lag, and bulk operations on non-indexed fields can cause collection or table scans, increasing resource usage. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replication-lag.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] On Atlas deployments, confirm the cluster state is `Active` in the Atlas UI, and on self-managed deployments, verify the `mongod` process is running and listening on the expected port. Sources: https://www.mongodb.com/docs/manual/troubleshooting/server-selection-timeout.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] A delayed member may show as 0 seconds behind the primary when the inactivity period on the primary is greater than the `members[n].secondaryDelaySecs` value. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replication-lag.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` ## Problems, failure modes and limitations - [low] Starting in MongoDB 6.1, slow query log messages include cache refresh time fields, and starting in MongoDB 7.0, they also include the `catalogCacheIndexLookupDurationMillis` field indicating operation time. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Error messages sent to `stderr`, such as fatal startup errors when not using file or syslog destinations, are not affected by the log output destination setting. Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] The `net.maxIncomingConnections` setting caps the total number of incoming connections a node holds open at one time, and when a node reaches its connection rate limit, Atlas queues new connection attempts, dropping some if the overload is sustained. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] The rollback time limit defaults to 24 hours and is configurable using the `rollbackTimeLimitSecs` parameter. Sources: https://www.mongodb.com/docs/manual/core/replica-set-rollbacks.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Starting in MongoDB 5.0, `enableMajorityReadConcern` is set to `true` and cannot be changed. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/manual/core/replica-set-rollbacks.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Use the `setParameter` command to modify the error threshold. Sources: https://www.mongodb.com/docs/manual/core/transactions-in-applications.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] An oplog should hold a minimum of 24 hours of operations, though many users prefer 72 hours or a week, and the oplog can grow past its configured size limit to avoid deleting the majority commit point. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replication-lag.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] On sharded clusters, each `mongos` router maintains connection pools on each shard, and you can limit the number of `taskExecutor` connection pools by setting the `taskExecutorPoolSize` parameter. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] If connection rejections occur with increased load and don't improve after adjusting pool settings, check whether `connections.current` is at or near the limit for your cluster tier, and consider upgrading to a higher tier if so. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Secondary members of a replica set log oplog entries that take longer than the slow operation threshold to apply under the `REPL` component with the text `applied op: took ms`. Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] MongoDB 8.3 introduces slow in-progress query log entries triggered during execution, which contain less information than standard slow query logs. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Distribute voting members across regions so that a majority remains available after a single-region failure. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` ## Comparisons and alternatives - [low] Starting in MongoDB 8.0, slow operations are logged based on the time MongoDB spends working on the operation rather than total latency, and the existing `queryHash` field is duplicated in a new field named `planCacheShapeHash`. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Atlas scales on memory and compute use rather than connections, but increased active connections may increase load and create a need to scale the cluster if other solutions are not viable. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` ## Facts and statements - [low] Applications should explicitly incorporate retry logic to handle `TransientTransactionError` and `UnknownTransactionCommitResult` errors. Sources: https://www.mongodb.com/docs/manual/core/transactions-in-applications.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Re-run `serverStatus` to verify that `connections.current` returned to expected levels relative to `connections.available`, and confirm that `mongod` or `mongos` logs no longer show connection-related errors. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Starting in MongoDB 6.3, log messages are added if the time to send an operation response exceeds the `slowms` threshold or if the wait between acquiring a server connection and writing bytes to the network exceeds 1 millisecond. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] The log message for the wait between acquiring a server connection and writing bytes to the network (added in MongoDB 6.3) is logged at the "I" information level by default, at most once every second, unless the log level is changed to debug to obtain every message. Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] MongoDB drivers can detect primary loss and automatically retry certain write operations a single time, and application connection logic should include tolerance for automatic failovers and subsequent elections. Sources: https://www.mongodb.com/docs/manual/core/replica-set-elections.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Atlas reserves 10 connections per node, and if the read preference is set to secondary, Atlas can read from the two secondary nodes for a combined 2980 connections. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Connection rate limits do not include connections from Atlas internal services, and Atlas reserves a small number of connections to each cluster for supporting Atlas services. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Cluster performance might degrade if it serves a large number of collections and indexes, with larger collections having a greater impact, and checkpoints take longer to complete, reducing operation speed. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] For MongoDB Search indexes on Atlas Core clusters, a high index count generates significant load on the base cluster and might disrupt workloads, and the number of indexes a cluster can support depends on the cluster tier and workload. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] For MongoDB Search indexes on Atlas Core clusters, start with a small number of indexes and monitor the cluster's resource usage as you scale. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Atlas connection limits apply per node, and for sharded clusters, they apply per `mongos` router, where the number of `mongos` routers equals the number of replica set nodes across all shards. Sources: https://www.mongodb.com/docs/atlas/reference/atlas-limits.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] The `createRollbackDataFiles` parameter controls whether rollback files are created during rollbacks, and you can search for `rollback file` in the MongoDB log to get the collection name. Sources: https://www.mongodb.com/docs/manual/core/replica-set-rollbacks.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Resize the oplog on each replica set member if you run MongoDB 4.0 or later using `db.adminCommand({ replSetResizeOplog: 1, size: })`, and size the oplog to maintain at least 72 hours of coverage at peak write volume. (verified as of 2026-10-15) Sources: https://www.netdata.cloud/guides/mongodb/mongodb-replication-lag/ — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Kill or redirect long-running reads and heavy aggregations on the secondary that compete for tickets and I/O using `db.currentOp()` to identify them and `db.killOp()` to abort, noting that `db.killOp()` aborts operations immediately and client requests may need retry logic. Sources: https://www.netdata.cloud/guides/mongodb/mongodb-replication-lag/ — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Check whether replication traffic competes with backups or cross-region traffic on the same network link, and isolate replication to dedicated bandwidth if possible. Sources: https://www.netdata.cloud/guides/mongodb/mongodb-replication-lag/ — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Disk-related issues are prevalent on multi-tenant systems and can be transient if disk devices are accessed over an IP network, with virtualization overhead from other VMs saturating the physical disk controller or under-provisioning where secondaries have slower disks or lower IOPS than the primary. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replication-lag.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Verify that outbound traffic from the client host is allowed on TCP port 27017 (or the configured custom port), and if needed for testing, temporarily allow access from `0.0.0.0/0`. Sources: https://www.mongodb.com/docs/manual/troubleshooting/server-selection-timeout.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Verify that the client driver supports TLS 1.2 or later, system root certificates are up to date, the certificate hostname matches the connection string, and the full certificate chain is available. Sources: https://www.mongodb.com/docs/manual/troubleshooting/server-selection-timeout.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Verify that your deployment does not have a primary by running `replSetGetStatus` or `rs.status()`, and once restored, the `rs.status()` output shows one member in the `PRIMARY` state. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] To avoid primary unavailability, perform rolling maintenance serially, starting with secondary members and ending with the primary, ensuring a primary is always available. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Run `autoCompact` only during periods of low traffic, such as a maintenance window, as background compaction on high-traffic databases can delay or prevent operational tasks like backups. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Once a majority of nodes can reach each other, MongoDB automatically elects a primary and writes resume normally. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Control the minimum and maximum number of connections in each router pool using the `ShardingTaskExecutorPoolMinSize` and `ShardingTaskExecutorPoolMaxSize` parameters. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Troubleshooting connection issues involves checking the output of `db.serverStatus()`, the driver connection string values for `maxPoolSize`, `minPoolSize`, and `waitQueueTimeoutMS`, the number of application instances and deployment topology, and a screenshot of the Atlas Connections graph over the issue period. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Indicators of connection issues include sudden increases in `connections.current` and `connections.active`, rapidly increasing `connections.totalCreated`, spikes in `metrics.network.totalIngressTLSHandshakeTimeMillis`, and increases in `metrics.commands..failed`. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] If you notice a high `connections.active` value and elevated query latency, set `minPoolSize` to a value closer to `maxPoolSize` in your driver connection string. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Starting in MongoDB 5.0, the `remoteOpWaitMillis` log field provides the wait time in milliseconds for results from shards, allowing diagnosis of whether waiting for shard responses or performing merges took the most time. (verified as of 2026-10-15) Sources: https://www.mongodb.com/docs/manual/reference/log-messages.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] To maximize the likelihood that a replica set member can become primary after a data center loss, distribute replica set members across data centers. Sources: https://www.mongodb.com/docs/manual/core/replica-set-elections.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] MongoDB measures elapsed rollback time as the time between the first common operation in the oplogs to the last entry in the oplog of the member being rolled back, which is the default rollback algorithm. Sources: https://www.mongodb.com/docs/manual/core/replica-set-rollbacks.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] If you disable "majority" read concern, MongoDB prevents collMod commands that modify an index from rolling back; to roll back such collMod commands, you must resync the affected nodes with the primary node. Sources: https://www.mongodb.com/docs/manual/core/replica-set-rollbacks.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Set the `wtimeout` parameter on write operations that use `"majority"` write concern to prevent writes from blocking indefinitely. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] If no secondaries are eligible to become primary due to their priority, update the `members[n].priority` value of one or more secondaries. Sources: https://www.mongodb.com/docs/manual/troubleshooting/replica-set-no-primary.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] On Atlas deployments, confirm that the connection count graph in the Atlas Metrics view has returned to baseline. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` - [low] Check deployment log messages for large numbers of `"Connection accepted"` messages with a rapidly increasing `connectionCount` attribute, or for other relevant indicators. Sources: https://www.mongodb.com/docs/manual/troubleshooting/connection-storms.md — source: `~/.global-ai-hub/research/.pipeline/mongodb-2026-10-14/frb/error-codes-and-troubleshooting-operational-runbook-e772bfd360/rabbithole-synthesis.md#troubleshooting` ## Related concepts - Troubleshooting — is a part of Error Codes and Troubleshooting Operational Runbook - and — is a part of Error Codes and Troubleshooting Operational Runbook - Error — is a part of Error Codes and Troubleshooting Operational Runbook - Operational — is a part of Error Codes and Troubleshooting Operational Runbook