mongosync States
On this page
mongosync enters different states depending on the requests it
receives. mongosync can only be in a single state at a given time.
The current mongosync states determines which API operations you can
run.
Note
Most state transitions happen as the result of an API call. The exceptions are:
The transition from
COMMITTINGtoCOMMITTED. For more information, see Finalizing Sync.The transition from
REVERSINGtoRUNNING. For more information, see Reversing Sync.
This page describes mongosync states.
View the Current State
To view the current state of mongosync, use the /progress. endpoint. The /progress
endpoint returns the state in the state field.
Note
Starting in mongosync 1.7.3, mongosync can take at least two minutes
to respond when you resume or restart a sync operation. During this time,
any calls to the progress endpoint might fail. If a
progress call fails, it is safe to retry.
State Descriptions
The following table describes each state and lists the permitted operations in that state.
State | Description | Possible API Operations |
|---|---|---|
| mongosync is initialized and ready for a sync job to
begin. | |
| The sync process is currently running. In this state, data is
initially synced to the destination cluster. Subsequent writes to
the source cluster are applied to the destination cluster. | |
| The sync process is paused. To resume the sync process, send a
request to the /resume endpoint. | |
| The cutover for the sync process has started. The time it takes
to transition to the COMMITTED phase depends on
lagTimeSeconds. To monitor lagTimeSeconds or to see if
mongosync has finished committing, use the /progress endpoint. |
|
| The cutover for the sync process is complete. | |
| The sync process copies metadata from the destination
cluster to the source cluster. Then, MongoDB swaps the
source and destination clusters and resumes applying
change events. |
|