Overview
Artifactory supports replication of repositories between two Artifactory instances to support development by different teams distributed over distant geographical sites. The benefits of replication are:
Ensuring developers all work with the same version of remote artifacts
Ensuring build artifacts are shared efficiently between the different development teams
Overcoming connectivity issues such as network latency and stability when accessing remote artifacts
Accessing specific versions of remote artifacts
Artifactory versions for replication
We strongly recommend that replication is only performed between servers running the same version of Artifactory.
Warning
We do not recommend using Artifactory repository replication in conjunction with AWS S3 cross-region replication of your filestore. Such a configuration can cause synchronization issues.
Note
Learn More > how to tune Cron Replication for a large number of artifacts.
Two main methods of replication are supported:
Both scheduled and event-based push replication are supported, and multi-push replication is available with an Enterprise license
Both scheduled and event-based pull replication are supported; event-based pull requires an Enterprise license.
Push Replication
Push replication is used to synchronize Local Repositories, and is implemented by the Artifactory server on the near end invoking a synchronization of artifacts to the far end.
There are two ways to invoke push replication:
Scheduled push: Pushes are scheduled asynchronously at regular intervals
Event-based push: Pushes occur in near-real-time since each create, copy, move or delete of an artifact is immediately propagated to the far end.
Advantages
It is fast because it is asynchronous.
It minimizes the time that repositories are not synchronized.
It reduces traffic on the master node in case of a replication chain ("Server A" replicates to "Server B", "Server B" then replicates to "Server C" etc.).
Avoid Replication Loops ("Cyclic Replication")
A replication loop occurs ("Cyclic" or "Bi-directional" replication) occurs when two instances of Artifactory running on different servers are replicating content from one to the other concurrently.
For example, "Server A" is configured to replicate its repositories to "Server B", while at the same time, "Server B" is configured to replicate its repositories to "Server A".
Or "Server A" replicates to "Server B" which replicates to "Server C" which replicates back to "Server A".
We strongly recommend avoiding cyclic replication since this can have disastrous effects on your system causing loss of data, or conversely, exponential growth of disk-space usage.
When to Use Push Replication
Event-based push replication is recommended when it is important for the repository at the far end to be updated in near-real-time for any change (create, copy, move or delete of an artifact) in the repository at the near end.
Regular scheduled replications run on top of event-based replication to guarantee full copy consistency even in cases of server downtime and network partitions.
Multi-push Replication
Requires an Enterprise License.
With an Enterprise license, Artifactory supports multi-push replication allowing you to replicate a local repository from a single source to multiple enterprise target sites simultaneously.
Pull Replication
This provides a convenient way to proactively populate a remote cache, and is very useful when waiting for new artifacts to arrive on demand (when first requested) is not desirable due to network latency.
There are two ways to invoke a pull replication:
Scheduled pull: Pull replication is invoked by a remote repository, and runs asynchronously according to a defined schedule to synchronize repositories (local, remote or virtual) at regular intervals.
Event-based pull: Requires an Enterprise License.
Pulls occur nearly in real-time since each create, copy, move or delete of an artifact is immediately propagated to the far end. As soon as a file is uploaded it is replicated and immediately available to the target (pulling) instance without even having to wait for the file upload to be completed at the source
Advantages
Many target servers can pull from the same source server efficiently implementing a one-to-many replication.
It is safer since each package only has one "hop".
It reduces traffic on target servers since they do not have to pass on artifacts in a replication chain.
When and when not to Use Pull Replication
Pull replication is recommended in the following cases:
When you need to replicate a repository to many targets.
When your source repository is located behind a proxy that prevents push replication (e.g. replicating a repository hosted on Artifactory SaaS to a local repository at your site)
Pull replication cannot be used to replicate a remote resource that is not an Artifactory repository. Artifacts from third party repositories can only be cached on-demand in the normal cache and proxy behavior of a Remote Repository
Scheduling and Configuring Replication
Using the UI
Replication is configured via the user interface as a scheduled task. Local repositories can be configured for push replication, and remote repositories can be configured for pull replication.
All replication messages are logged in the main Artifactory Log file.
The Replications column in your list of local repositories indicates if replication is configured for each repository in the list. If replication is indeed configured for a repository, you can click the icon in the list to invoke it.
Configuring Push Replication
A push replication task for a Local Repository is configured in the Replication tab of the Configuring a Local Repository dialog.
First, in the Cron Expression field define the replication task schedule using a valid cron expression.
The Next Replication Time will indicate update accordingly.
Cron Expression VS Event Base Replication
Replication of this repository to all of its targets occurs simultaneously according to the Cron Expressionyou define.
The event base replication will attempt to replicate only the artifacts affected by the event while the Cron Expression will trigger a sync of all artifacts in repository. This difference is important since in case one of the event sync has failed the next time the Cron Expression will trigger a sync all changed will be synced.
Once you have configured the replication properties for each of your replication targets, the Replication tab for your repository displays them.
Field | Description |
---|---|
Destination URLs | The replication targets you have defined |
Enabled | When set, enables replication of this repository to the target specified in Push to |
Enable Event Replication | When set, each event will trigger replication of the artifacts changed in this event. This can be any type of event on artifact, e.g. add, deleted or property change. |
Number of replication targets
If you do not have an Enterprise license, you may only define one replication target. With an Enterprise license, Artifactory supports multi-push replication and you may define as many targets as you need.
Adding a push replication target
To add a target site for this replication, click Add to display the Replication Properties dialog, and fill in the details as follows.
Field | Description |
---|---|
Enable Active Replication of this Repository | When set, this replication will be enabled when saved |
URL | The URL of the target local repository on a remote Artifactory server. Use the format |
Username | The HTTP authentication username. |
Credentials | Use either the HTTP authentication password or identity token |
Proxy | A proxy configuration to use when communicating with the remote instance. |
Socket Timeout | The network timeout in milliseconds to use for remote operations. |
Sync Deleted Artifacts | When set, items that were deleted locally should also be deleted remotely (also applies to properties metadata). Note that enabling this option, will delete artifacts on the target that do not exist in the source repository. |
Sync Artifact Properties | When set, the task also synchronizes the properties of replicated artifacts. |
Sync Artifact Statistics | When set, the task also synchronizes artifact download statistics. Set to avoid inadvertent cleanup at the target instance when setting up replication for disaster recovery. |
Path Prefix (optional) | Only artifacts that located in path that matches the subpath within the repository will be replicated. |
Configuring Pull Replication
A pull replication task for a Remote Repository is configured in the Replication tab of the Edit Remote Repositories dialog.
First, in the Cron Expression field define the replication task schedule using a valid cron expression.
The Next Replication Time will indicate update accordingly.
Field | Description |
---|---|
Enable Active Replication of this Repository | When set, this replication will be enabled when saved |
URL | The URL of the target local repository on a remote Artifactory server. Use the format For some package types, you need to prefix the repository key in the URL with |
Enable Event Replication | When set, each event will trigger replication of the artifacts changed in this event. This can be any type of event on artifact, e.g. added, deleted or property change. |
Sync Deleted Artifacts | When set, items that were deleted locally should also be deleted remotely (also applies to properties metadata). |
Sync Artifact Properties | When set, the task also synchronizes the properties of replicated artifacts. |
Path Prefix (optional) | Only artifacts that located in path that matches the subpath within the remote repository will be replicated. |
Regarding credentials of the remote repository configuration
The remote repository's file listing for replication is retrieved using the repository's credentials defined under the repository's Advanced configuration section.
The remote files retrieved depend on the effective permissions of the configured user on the remote repository (on the other Artifactory instance).
* Check for which package formats you need to prefix the repository path with api/<pkg>
For some packaging formats, when using the corresponding client to access a repository through Artifactory, the repository key in the URL needs to be prefixed with api/<pkg>
in the path. For example, in the case of NPM repositories, the repository key should be prefixed with api/npm
.
Nevertheless, there are exceptions to this rule. For example, when replicating Maven repositories, you do not need to add a prefix the remote repository path.
The considerations of whether to prefix the repository key with api/<pkg>
or not are the same as those when configuring smart remote repositories. For a detailed list of package formats that should be prefixed with api/<pkg>
, please refer to Configuration under Smart Remote Repositories.
Replicating with REST API
Both Push and Pull Replication are supported by Artifactory's REST API. For details please refer to the following:
Replication Properties
Once replication has been invoked, the system annotates the source repository being replicated and annotates it with properties that indicate the status of the replication. These can be viewed, along with other properties that may annotate the repository, in the Properties tab of the Tree Browser.
For single push replication operations, the following properties are created/updated:
Key | Value |
---|---|
| Indicates when the replication started |
| Indicates the status of the replication operation once complete. It can take the following values: ok: The replication succeeded failure: The replication failed. You should check the log files for errors |
| Indicates when the replication finished |
For multi-push replication operations (available to Enterprise customers only), the following properties are created/updated:
Key | Value |
---|---|
| Indicates when the replication started |
| Indicates the status of the replication operation once complete. It can take the following values: ok: The replication succeeded failure: The replication failed. You should check the log files for errors |
| Indicates when the replication finished |
Optimizing Repository Replication Using Storage Level Synchronization Options
Note
Requires an Enterprise+ license.
You can set Artifactory to offload the heavy-lifting work of replicating data to the storage device, by only replicating the metadata while ensuring the data is available on the target binary store. This is recommended, for example, when you have two Artifactory instances configured with replication between them. The binary provider configured on Artifactory includes integrated support for replicating data on the storage level, allowing you to assign the replication process to the storage.
To run repository replication using storage level synchronization options:
Synchronize the storage devices for the source and target Artifactory systems.
Set the
checkBinaryExistenceInFilestore
flag to true in the Push or Pull Replication API commands in the source Artifactory. For more information, see the Pull/Push Replication, Set Repository Replication, and Update Repository Replication API commands.Set the
checkBinaryExistenceAllowed
flag to true in the target Artifactory with thechecksumReplication
API command. For more information, see Configure Checksum Replication and Get Checksum Replication API commands.
Enabling the Flag During Replication
When enabling the flag, during replication, Artifactory searches for the binary in the target Artifactory instance in the binary storage and if it exists, the source replicates only the metadata.
It is the user's responsibility to replicate the data on the storage level.
This feature is disabled by default and does not change any behavior.
Watch the Screencast
To see replication in action, watch the short screencast below.