ArcGIS Data Store allows you to create highly available or scalable data stores by including more than one machine in each type of data store that you deploy.
Options for adding machines vary by data store type and are explained as follows:
Relational data stores
The first machine on which you install ArcGIS Data Store and create a relational data store is the primary relational data store machine. You can install and configure one other relational data store with the same GIS Server site, making this second relational data store machine your standby machine. Hosted feature layer data is replicated from the primary to the standby.
If the primary becomes unavailable (for example, if the primary machine crashes, loses power, or loses network connectivity), the standby machine is promoted to primary. You will only be without your hosted feature layer data for the period of time it takes for the standby machine to become the primary—this can take up to a few minutes. Once the standby becomes the primary relational data store, it sends its backup files to the same location as the former primary machine.
If you can correct the problem with the former primary machine—for example, if the machine was unplugged and you plugged it back in, or the machine temporarily lost network connectivity but network connectivity was later restored—the former primary becomes the standby machine for the relational data store.
For information about when a relational data store fails over, see ArcGIS Data Store deployment modes.
Tile cache data stores
The number of machines you can add to a tile cache data store depends on the deployment mode you use.
- In primary-standby mode, a tile cache data store can contain a single machine or, to provide fail-over functionality, it can contain two machines. The tile cache data store defaults to primary-standby mode.
The first machine on which you install ArcGIS Data Store and create a tile cache data store is the primary tile cache data store machine. You can install and configure one other tile cache data store with the same GIS Server site, making this second tile cache data store machine your standby machine. Hosted scene layer cache data is replicated from the primary to the standby machine. Similar to relational data stores, the standby becomes primary if the primary machine fails.
When both primary and standby machines are running, ArcGIS can use the primary or the standby tile cache data store machine when processing read-only queries. This improves performance when you're viewing a hosted scene layer.
For information about when a tile cache data store running in primary-standby mode fails over, see ArcGIS Data Store deployment modes.
- In cluster mode, a tile cache data store can contain multiple data store machines to provide for scalability.
When hosted layers are published, the hosted scene layer cache data is duplicated on two of the tile cache data store machines.
You can also add tile cache data store machines to meet demand. If you're running out of space on the current machines, install ArcGIS Data Store on additional machines and register them with the same hosting GIS Server site. When you do, caches for new scene layers will be distributed on the new machines. Existing scene caches remain on the original machines.
To rebalance the existing caches to use the newly added machines, you must create a backup of the tile cache data store and restore it. For instructions, see Rebalance scene layer caches.
Recovery after loss of a tile cache machine in cluster mode
If you have multiple machines in your tile cache data store for the purpose of high availability and one of the machines is lost or goes offline, you may need to redistribute scene cache data.
Attempt to bring the failed machine back online. For example, if a network or power cable is unplugged or the machine was shut off, you can rectify the issue by plugging in the network or power cable or turning on the computer. Once back online, the machine rejoins the tile cache data store and the data store continues to function.
If a machine crashes and cannot be resurrected, you need to take steps to ensure your scene layer caches are still highly available. See Recover a data store for instructions.
Spatiotemporal big data stores
You can install ArcGIS Data Store on several machines, create spatiotemporal big data stores on each, and register each one with the same hosting GIS Server site.
Note:
Always use an odd number of machines in your spatiotemporal big data store.
Data in the spatiotemporal big data store is duplicated on at least two spatiotemporal big data store machines registered to the same hosting server.
If any one machine fails, data still exists on at least one other machine. The data store replicates the data to another machine that is still functional.
You can install ArcGIS Data Store on more machines and create spatiotemporal big data stores that are registered with the same GIS Server sites. In this example, three machines are added: one to replace the one that failed, and two more to accommodate increased numbers of hosted spatiotemporal feature layers. Data is rebalanced across all seven machines. Data for newly published spatiotemporal feature layers is also distributed.
Note:
If you script the creation of multiple spatiotemporal big data store machines, one spatiotemporal big data store machine must be manually configured with the GIS Server site before you can script the creation of additional spatiotemporal big data store machines. Include wait times in your script to be sure the additional spatiotemporal big data store machines are not added at the same time.
Graph stores
Graph stores created with ArcGIS Data Store 11.2 and later can contain one or two machines. If you require a highly available graph store, configure a graph store that contains two machines.
The first machine on which you install ArcGIS Data Store and create a graph store is the primary graph store machine. You can install and configure one other graph store with the same GIS Server site, making this second machine your standby graph store machine. Hosted knowledge graphs are replicated from the primary to the standby.
If the primary becomes unavailable (for example, if the primary machine crashes, loses power, or loses network connectivity), the standby machine is promoted to primary. You will only be without your knowledge graph data for the period of time it takes for the standby machine to become the primary—this can take up to a few minutes. Once the standby becomes the primary graph store, it sends its backup files to the same location as the former primary machine.
If you can correct the problem with the former primary machine—for example, if the machine was unplugged and you plugged it back in, or the machine temporarily lost network connectivity but network connectivity was later restored—the former primary becomes the standby machine for the graph store.
For information about when a graph store fails over, see ArcGIS Data Store deployment modes.
Legacy:
Graph stores created with ArcGIS Data Store 11.1 or earlier can contain only one machine.
Object store
You can create an object store that contains one machine or you can deploy an object store in cluster mode that contains three or more machines.
A single-machine object store with a large amount of disk space can provide you adequate drawing performance when viewing feature layers that are configured to use cached query responses. However, if you require scalability for cached feature query responses, deploy the object store in cluster mode when you create it. You cannot change modes after deploying.
If you deploy the object store in cluster mode, you can add machines to the object store cluster if the existing machines get overloaded. Similarly, if one of the machines in the object store cluster fails and you can't bring it back online, you can install ArcGIS Data Store on a new machine, and configure it as object store with the same hosting server to add the new machine to the cluster.
When you enable query caching on new feature layers, the cached query responses for the new layers will use the new machine in the cluster. Newly published video services will also use the new machine.
Add a machine to a data store
Use the Data Store Configuration wizard or the configuredatastore utility to add a machine to any data store.
You can have one standby relational data store, graph store, or tile cache data store that is running in primary-standby mode. You can have multiple machines in a spatiotemporal big data store and in a tile cache data store or object store that is running in cluster mode. All machines that participate in the same data store must use the same operating system and be the same ArcGIS Data Store release.
Use the Data Store Configuration wizard to add a machine to a data store
Follow these steps to use the Data Store Configuration wizard to add a machine to data store:
- Install ArcGIS Data Store on another server.
Each standby machine, primary machine, or node in a cluster must be installed on different physical servers. Use the same network account for the ArcGIS Data Store account on all machines in the data store.
- Open the ArcGIS Data Store Configuration wizard.
- Specify the fully qualified name of one of the machines in the GIS Server site.
The name is in the format gisserver.domain.com. Use the same GIS Server site as you did when configuring the other machine or machines in the same data store for this ArcGIS Enterprise deployment.
- Type the username and password of the ArcGIS Server primary site administrator and click Next.
- Choose the type of data store to create.
- Specify a location for the new data store's directory and click Next.
- Review the information in the Configuration Summary. If it is correct, click Finish. If changes are needed, click Back to make corrections.
The High Availability Role indicates that this is a standby machine for relational data stores.
When the setup completes successfully, you have an additional data store machine to which ArcGIS Data Store can replicate data or caches.
If there were errors with the setup, click Next on the Configuration Summary dialog box to reopen the Data Store Configuration wizard so you can provide different information. See Troubleshoot ArcGIS Data Store for causes and resolutions to setup errors.
Use the configuredatastore utility to add a machine to a data store
You can install ArcGIS Data Store on another server or servers and use the configuredatastore utility to add it to an existing data store. The utility is installed in <ArcGIS Data Store installation directory>\arcgis\datastore\tools.
Each standby machine, primary machine, or node in a cluster must be installed on different physical servers.
Note:
You must use the same network account for the ArcGIS Data Store account on all machines in the data store.
Follow these steps to use the configuredatastore utility to add a machine to a data store:
- Open a command shell on the additional server where you installed ArcGIS Data Store.
- Run the configuredatastore utility, and provide the fully qualified domain name of a machine in the GIS Server site and the ArcGIS Server primary site administrator username and password.
Use the --stores operation to specify the type of data store to be created.
You must specify the same GIS Server machine name and data store type that you used for the data store to which you want to add this machine.
For example, the following adds a standby relational data store to a machine in the GIS Server site with the fully qualified name of agsserver.ntwk.com. The data store directory on this machine is /home/dsuser/fsdata.
/configuredatastore agsserver.ntwk.com siteadmin P$@pass /home/dsuser/fsdata --stores relational
Another data store machine is added to the data store.
See the configuredatastore section of the ArcGIS Data Store utility reference for syntax and more examples.