Inter-Sync Gateway Replication Configuration
Using Sync Gateway’s Admin REST API to configure and manage inter-Sync Gateway replications
Related topics: Overview | Bootstrap | Database | Database Security | Access Control | Import | Inter-Sync Gateway Replication
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Pre-3.0 Legacy Configuration Equivalents
This content describes configuration for Sync Gateway 3.0 and higher — for legacy configuration, see: Legacy Pre-3.0 Configuration |
Introduction
Sync Gateway 3.0 and later uses the Admin REST API to provision persistent configuration changes. This page introduces the PUT/{url}/{db}/_replication/{replicationId} endpoint for convenience — see Replication for a full description of the endpoints available.
Upsert a Replication
For complete endpoint details, see PUT/{url}/{db}/_replication/{replicationId}.
Example
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Curl
-
HTTP
curl --location --request PUT 'http://localhost:4985/db1-local/_replication/db1-rep-id1 '\
--header 'Content-Type: application/json' \
--data-raw '{
"direction": "push",
"purge_on_removal": false,
"remote": "http://user1:password1@example.com:4984/db1-remote",
"filter":"sync_gateway/bychannel",
"query_params": {
"channels":["channel.user1"]
},
"continuous": false
}'
PUT /db1-local/_replication/db1-rep-id1 HTTP/1.1
Host: localhost:4985
Content-Type: application/json
Content-Length: 235
{"direction": "push",
"purge_on_removal":false,
"remote": "http://user1:password1@example.com:4984/db1-remote",
"filter":"sync_gateway/bychannel",
"query_params": {
"channels":["channel.user1"]
},
"continuous": false
}
Schema
This section shows the replication configuration settings in schema format. Use these schemas to construct JSON models for the Admin REST API.
The configuration settings described here are provisioned through the Replication endpoints.
{
adhoc: false,
batch_size: 200,
collections_enabled: false,
collections_local: ["string"...],
collections_remote: ["string"...],
conflict_resolution_type: "default",
continuous: false,
custom_conflict_resolver: "",
direction: "string",
enable_delta_sync: false,
filter: "string",
initial_state: "running",
max_backoff_time: 5,
purge_on_removal: false,
query_params: ["string"...],
remote: "string",
remote_password: "string",
remote_username: "string",
replication_id: "string",
run_as: "string"
}
adhoc
Type: boolean
Set to true to run the replication as an adhoc replication instead of a persistent one.
This means that the replication will only last the period of the replication until the status is changed to stopped and then it will be removed automatically. It will also be removed if Sync Gateway restarts or if removed due to user action.
batch_size
Type: integer (Default 200)
The amount of changes to be sent in one batch of replications. Changing this is an Enterprise Edition only feature.
collections_enabled
Type: boolean
If true, the replicator will run with collections, and will replicate all collections, unless otherwise limited by collections_local.
If false, the replicator will only replicate the default collection.
collections_local
Type: array
Limits the set of collections replicated to those listed in this array.
The replication will use all collections defined on the database if this list is empty.
collections_remote
Type: array
Remaps the local collection name to the one specified in this array when replicating with the remote.
If only a subset of collections need remapping, elements in this array can be specified as null to preserve the local collection name.
The same index is used for both collections_remote and collections_local, and both arrays must be the same length.
conflict_resolution_type
Type: string (Default default)
This defines what conflict resolution policy Sync Gateway should use to apply when resolving conflicting revisions.
Changing this is an Enterprise Edition only feature.
continuous
Type: boolean
If true, changes will be immediately synced when they happen. This is known as a continuous replication.
If false, all changes will be synced until they have been processed. The replication will then cease and not process any future changes (unless started again by the user). This is known as a one-shot replication.
custom_conflict_resolver
Type: string
This specifies the Javascript function to use to resolve conflicts between conflicting revisions.
This must be used when conflict_resolution_type=custom. This property will be ignored when conflict_resolution_type is not custom.
The Javascript function to provide this property should be in backticks (like the sync function). The function takes 1 parameter which is a struct that represents the conflict. This struct has 2 properties:
LocalDocument- The local document. This contains the document ID under the_idkey.RemoteDocument- The remote document The function should return the new document's body. This can be the winning revision (for example,return conflict.LocalDocument), a new body, ornilto resolve as a delete.
Example:
function(conflict) {
console.log("Doc ID: "+conflict.LocalDocument._id);
console.log("Full remote doc: "+JSON.stringify(conflict.RemoteDocument));
return conflict.RemoteDocument;
}
Using complex custom_conflict_resolver functions can noticeably degrade performance. Use a built-in resolver whenever possible.
If a document merge is being done, the _rev and _cv properties should not be included in the returned document body as Sync Gateway will generate new values for these.
This is an Enterprise Edition only feature.
direction
Type: string
This specifies which direction the replication will be replicating with the remote replicator.
enable_delta_sync
Type: boolean
This will turn on delta-sync for the replication. In order to enable delta-sync for a replication, the database level setting delta_sync.enabled must also be set to true.
Using delta-sync is an Enterprise Edition only feature.
filter
Type: string
This defines whether to filter documents.
initial_state
Type: string (Default running)
This is what state to start the replication in when creating a new replication.
This allows you to control if the replication starts in a stopped start or running state.
Replications prior to Sync Gateway 2.8 will run in the default state running.
max_backoff_time
Type: integer (Default 5)
Specifies the maximum time-period (in minutes) that Sync Gateway will attempt to reconnect to a lost or unreachable remote.
When a disconnection happens, Sync Gateway will do an exponential backoff up to this specified value. When this value is met, it will attempt to reconnect indefinitely every max_backoff_time minutes.
If this is set to 0, Sync Gateway will do the normal exponential backoff after the disconnect happens but then attempting 10 minutes and stop the replication.
Note: this defaults to 5 minutes for replications created prior to Sync Gateway 2.8.
purge_on_removal
Type: boolean
Specifies whether to purge a document if the remote user loses access to all of the channels on the document when attempting to pull it from the remote.
If false, documents will not be replicated and not be purged when the user loses access.
query_params
Type: array
This is a set of key/value pairs used in the query string of the replication.
If filters=sync_gateway/bychannel then this can be used to set the channels to filter by in a pull replication. To do this, set the channels key to a string array of the channels to filter by. For example:
"filter":"sync_gateway/bychannel",
"query_params": {
"channels":["chanUser1"]
},
remote
Type: string
This is the endpoint of the database for the remote Sync Gateway that is the subject of this replication's push, pull, or pushAndPull action.
Typically this would include the URI, port, and database name. For example, https://localhost:4985/db.
remote_password
Type: string
The password to use to authenticate with the remote. This password will be redacted in the replication config.
remote_username
Type: string
The username to use to authenticate with the remote.
replication_id
Type: string
This is the ID of the replication.
When creating a new replication using a POST request, this will be set to a random UUID if not explicitly set.
When the replication ID is specified in the URL, this must be set to the same replication ID if specifying it at all.
run_as
Type: string
This is used if you want to specify a user to run the replication as. This means that the replication will only be able to replicate what the user access to what the user has access to.