ThingWorx Model Definition and Composer > Data Storage > Persistence Providers > Using DataStax Enterprise as the Persistence Provider
  
Using DataStax Enterprise as the Persistence Provider
If your model requires big data scalability, you can use DataStax Enterprise (DSE) as the persistence provider via an extension import in ThingWorx. The extension DsePersistenceProviderPackage.zip is built to use the DataStax Enterprise edition of Cassandra (not the Open Source/Community Edition), which has the Solr search engine as an integrated offering. DSE is a big data platform built on Apache Cassandra that manages real-time, analytics, and enterprise search data.
Cassandra is a scalable open source NoSQL database that can manage large amounts of data across multiple data centers and the cloud. Cassandra delivers continuous availability, linear scalability, and operational simplicity across many commodity servers with no single point of failure, along with a powerful data model designed for maximum flexibility and fast response times.
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Getting started with DSE requires you to register, install, and configure DSE. Most of this process is performed independently of ThingWorx and is documented in the Getting Started with DataStax Enterprise and ThingWorx guide. This guide provides recommendations and links to resources that will help you plan and implement DSE.
High Level Process for DSE Implementation
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All the steps below are described in detail in the Getting Started with DataStax Enterprise and ThingWorx guide.
1. Determine if DSE is the right solution for your data. Refer to the sizing and planning sections for additional information.
2. Register and install DSE.
This process is performed independently of ThingWorx. A deployment example is provided in the guide.
3. Import the DSE persistence provider extension into ThingWorx.
4. Create a persistence provider instance in ThingWorx that will connect the DSE data store.
5. Configure the settings for the persistence provider in ThingWorx.
Name
Default Value
Description
Connection Information
Cassandra Cluster Hosts
192.168.234.136,192.168.234.136
IP address(es) for the Cassandra cluster(s). These are the IP addresses or the host names configured during DSE setup to install the Cassandra cluster.
Cassandra Cluster Port
9042
The port for the Cassandra cluster configured during DSE setup to install the Cassandra cluster.
Cassandra User Name
n/a
Optional, unless you want to enable authentication on a cluster. In that case, this field is required.
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Enabling the authentication needs to be done in the Cassandra cluster. The user requires the appropriate authorization level to create a keyspace.
Cassandra Password
n/a
Optional, unless you want to enable authentication on a cluster In that case, this field is required. (See above.)
Cassandra Keyspace Name
thingworxnd
The location that ThingWorx data points to. Similar to a schema in a relational database.
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If you are upgrading from version 1.0 of the DsePersistenceProviderPackage.zip, this field is required.
Solr Cluster URL
http://localhost
If data tables are being used, provide IP or fully qualified host name including the domain or the IP configured during DSE setup to install the Cassandra cluster.
Solr Cluster Port
8983
If data tables are being used, provide the port configured during DSE setup to install the Cassandra cluster.
Cassandra Keyspace Settings
replication = {'class':'NetworkTopologyStrategy', 'Cassandra':1, 'Solr':1}
Dependent on your Cassandra cluster configuration created during DSE setup. Primarily defines the data centers used and the associated replication factors (refer to http://datastax.com/documentation/cql/3.1/cql/cql_reference/create_keyspace_r.html for details). If the administrators created the keyspace manually, then these settings should match the manually created keyspace settings.
Cassandra Consistency Levels
{'Cluster' : { 'read' : 'ONE', 'write' : 'ONE' }}
Read and write consistency levels for the number of nodes.
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Implement more than one node to include a redundancy copy for the writes. For more information, refer to http://datastax.com/documentation/cassandra/2.1/cassandra/dml/dml_config _consistency_c.html.
CQL Query Result Limit
5000
Cassandra Query Language query result limit specifies the number of row returned when querying the data. This enhances the stability of ThingWorx by not allowing large results sets that would cause performance issues in the Platform to be returned.
Keep Connection Alive
true
Helps to keep the connections to the Cassandra cluster alive, especially across firewalls, where the inactive connections could be dropped.
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Do not implement firewalls between ThingWorx and the Cassandra cluster.
Connection Timeout (Millis)
30000
Initial connection time-out in milliseconds. Depends on the network latency between ThingWorx and the Cassandra cluster.
Compression Algorithm
none
When ThingWorx sends data to a cluster, there are three options:
Lz4 compression
Snappy compression
No compression
If the network bandwidth between ThingWorx and the Cassandra cluster is low, then using a compression will increase the throughput.
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The compression will consume more CPU cycles in the machine running ThingWorx.
Maximum Query Retries
3
The maximum number of retries enabled for queries. The default is three.
Local Core Connections
4
Minimum number of connections that are able to read/ write data.
Local Max Connections
16
Maximum number of connections that are able to read/write data
Remote Core Connections
2
Minimum number of remote connections that are able to read/write data.
Remote Max Connections
16
Maximum number of remote connections that are able to read/write data
Enable Tracing
false
Logging. Can be enabled for debugging.
Max Async Requests
1000
Classic Stream Settings
Cache Initial Size
10000
The initial cache size. This is dependent on the number of sources.
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Use more than the number of configured sources.
Cache Maximum Size
100000
The max cache size. Controls memory usage.
Cache Concurrency
24
The number of threads you can access at the same time. The minimum value should reflect the value set for Remote Max Connections.
Classic Stream Defaults
Source Bucket Count
1000
Sources can be put into buckets. The number of sources equals the number of queries that need to be executed. For example, if you have 100,000 sources, this field determines how many buckets are used.
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Data may not be accessible via ThingWorx if this setting is changed after data has been written. If you need to change this after data has been written, export data before changing this setting, then reimport data.
Time Bucket Size (Hours)
24
The time (in hours) to create buckets. Dependent on how the source bucket size is set up. For example, if the Time Bucket Size is set to 24, buckets will be created every 24 hours. The goal is to try not to exceed 2 million data points. So, depending on the data ingestion rate (R per second) per value stream or classic stream: Time Bucket Size = 2 mil / (R * 60 * 60)
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Data may not be accessible via ThingWorx if this setting is changed after data has been written. If you need to change this after data has been written, export data before changing this setting, then reimport data.
Data Table Defaults
Data Table Bucket Count
3
A data table can be split into buckets. This allows a data table to be spread across DSE nodes. A value higher than the number of nodes in the cluster is recommended to allow data spread when the number of nodes increases depending on the load. The other factor to consider is the number of rows expected in the data table. Consider limiting to 200,000 rows per bucket. The setting here is the default. The bucket count can be specified per data table.
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Data may not be accessible via the Platform if this setting is changed after data has been written. If you need to change this after data has been written, export data before changing this setting, then reimport data.
Value Stream Settings
Cache Initial Size
10000
The initial cache size. This is dependent on the number of sources multiplied by number of properties per source.
Cache Maximum Size
100000
The maximum cache size. Controls memory usage.
Cache Concurrency
24
The number of threads you can access at the same time.
Value Stream Defaults
Source Bucket Count
1000
Sources can be put into buckets. The number of sources equals the number of queries that need to be executed. For example, if you have 100,000 sources, this field determines how many buckets are used.
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Data may not be accessible via ThingWorx if this setting is changed after data has been written. If you need to change this after data has been written, export data before changing this setting, then reimport data.
Property Bucket Count
1000
The number of buckets depends on the number of properties per value stream and the query pattern. If there are queries spanning across properties, a smaller bucket size will yield the best performance.
Time Bucket Size (Hours)
24
The size of the bucket(s). Dependent on how the source bucket size is set up. For example, if the Time Bucket Size is set to 24, buckets will be created every 24 hours.
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Data may not be accessible via the Platform if this setting is changed after data has been written. If you need to change this after data has been written, export data before changing this setting, then reimport data.
6. If necessary, migrate entities and data.
7. Monitor and maintain your DSE implementation. Best practices for creating a successful maintenance plan are described in the guide.
For streams, value streams, and data tables, you can configure bucket settings. These settings override the DSE persistence provider instance configuration.