Fix Atlas Search Issues
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Atlas Search triggers Atlas Search alerts when the amount of CPU and memory used
by Atlas Search processes reaches a specified threshold. If the search
process (mongot) runs out of memory, indexing and
queries fail. You can configure Atlas Search alert conditions in the project
alert settings modal. You can also view Atlas Search
metrics with cluster monitoring.
Alert Conditions
You can configure the following alert conditions in the project-level alert settings page to trigger alerts.
Atlas Search: Index Replication Lag occurs if the approximate
number of milliseconds that Atlas Search is behind in replicating changes from
the oplog of mongod is above or below the threshold.
Atlas Search: Index Size on Disk occurs if the total size of all
Atlas Search indexes on disk in bytes is above or below the threshold.
Atlas Search: Number of Error Queries occurs if the number of
queries for which Atlas Search is unable to return a response is above or
below the threshold.
Atlas Search: Number of Index Fields occurs if the total number
of unique fields present in the Atlas Search index is above or below the
threshold.
Atlas Search: Number of Successful Queries occurs if the number
of queries for which Atlas Search successfully returned a response is above or
below the threshold.
Atlas Search: Total Number of Queries occurs if the number of
queries submitted to Atlas Search is above or below the threshold.
Atlas Search Opcounter: Delete occurs if the total number of
documents or fields (specified in the index definition) removed per
second is above or below the threshold.
Atlas Search Opcounter: Getmore occurs if the total number of
getmore commands run on all Atlas Search queries per second is above or
below the threshold.
Atlas Search Opcounter: Insert occurs if the total number of
documents or fields (specified in the index definition) that Atlas Search
indexes per second is above or below the threshold.
Atlas Search Opcounter: Update occurs if the total number of
documents or fields (specified in the index definition) that Atlas Search
updates per second is above or below the threshold.
Insufficient disk space to support rebuilding search indexes
occurs if your database deployment runs out of enough free disk
space to support your Atlas Search indexes.
This alert might appear when Atlas automatically upgrades your search indexes to enable new features. Your database deployment must have sufficient disk space for both the previous and new version of the index. After the index upgrade completes, Atlas deletes the old version of the index, which frees up disk space.
Search Memory: Resident occurs
if the total bytes of resident memory occupied by the Atlas Search process is
above or below the threshold.
Search Memory: Shared occurs if
the total bytes of shared memory occupied by the Atlas Search process is above
or below the threshold.
Search Memory: Virtual occurs if
the total bytes of virtual memory occupied by the Atlas Search process is
above or below the threshold.
Search Process: CPU (Kernel) % occurs if the percentage of time
the CPU spent servicing operating system calls for the Atlas Search process is
above the threshold.
Search Process: CPU (User) %
occurs if the percentage of time the CPU spent servicing the Atlas Search
process is above the threshold.
Search Process: Disk space used occurs if the total bytes of disk
space used by the Atlas Search process is above the threshold.
Search Process: Ran out of memory occurs if the search process
(mongot) runs out of memory. If the search process runs out of
memory, indexing and queries fail.
The Search Process: Ran out of memory alert runs
automatically by default. You can configure the alert setting to disable this notification.
Common Triggers
Atlas Search alerts often occur when you try to build a large or complex search index. These indexes remain in the Initial Sync phase until you resolve the memory issue.
Fix the Immediate Problem
If the search process (mongot) runs out of memory or disk space,
you can upgrade your cluster to fix the
immediate problem. You can select a cluster tier with more memory,
storage, and IOPS.
Implement a Long-Term Solution
To prevent Atlas Search alerts in the future, carefully review the Tune Performance for Atlas Search. Work to optimize your indexes.
Monitor Your Progress
View the available Atlas Search charts to monitor Atlas Search metrics.
Monitor Atlas Search metrics to evaluate and optimize your Atlas Search indexes.
To learn more, see View Cluster Metrics