wikimedia/restbase-mod-table-cassandra

This projects provides a high-level table storage service abstractionsimilar to Amazon DynamoDB or Google DataStore on top of Cassandra. As theproduction table storage backend for RESTBase, it powers theWikimedia REST APIs, such as this one for the EnglishWikipedia.For testing and small installs, there is also a sqlite backendimplementing the same interfaces.Issue trackingWe use Phabricator to trackissues. See the list of current issues in restbase-mod-table-cassandra.StatusIn production since March 2015.Featuresbasic table storage service with REST interface, backed by Cassandra,implementing the RESTBase table storage interfacemulti-tenant design: domain creation, prepared for per-domain ACLstable creation with declarative JSON schemaslimited automatic schema migrationspagingTODOPossibly, some amount of transaction supportLeverage Cassandra 3 materializedviews where it makes sense,once those have stabilized.ConfigurationConfiguration of this module takes place from within an x-modules stanza in the YAML-formattedRESTBase configuration file.While complete configuration of RESTBase is beyond the scope of this document, (see theRESTBase docs for that), this section covers therestbase-mod-table-cassandra specifics. - name: restbase-mod-table-cassandra version: 1.0.0 type: npm options: # Passed to the module constructor conf: version: 1 hosts: [localhost] username: cassandra password: cassandra defaultConsistency: localOne localDc: datacenter1 datacenters: - datacenter1 storage_groups: - name: default.group.local domains: /./VersionThe version of this configuration. Each edit of the module configuration mustcorrepond to a new, unique version.Note: Versions must be monotonically increasing. version: 1HostsA list of Cassandra nodes to use as contact points. hosts: - cassandra-01.sample.org - cassandra-02.sample.org - cassandra-03.sample.orgCredentialsPassword credentials to use in authenticating with Cassandra.Note: Optional; Leave unconfigured if Cassandra authentication is not enabled. username: someuser password: somepassDefault ConsistencyThe Cassandra consistency level to use when not otherwise specified. Validvalues are those from the nodejs driver for Cassandra.Defaults to localOne. defaultConsistency: localOneTLSKey and certificate information for use in TLS-encrypted environments. See thenodejs documentation on tls.connectfor the meaning of these directives.Note: Optional; Leave unconfigured if Cassandra client encryption is not enabled. tls: cert: /etc/restbase/tls/cert.pem key: /etc/restbase/tls/key.pem ca: - /etc/restbase/tls/root.pemLocal Datacenterrestbase-mod-table-cassandrauses a datacenter-aware connection pool. The localDc directive instructs the modulewhich datacenter to treat as 'local' to this instance. Cassandra nodes in the localdatacenter will be used for queries, and any others serve as a fallback. Defaults todatacenter1 (the Cassandra default).Note: the localDc must be in the list of configured datacenters (see below). localDc: datacenter1DatacentersThe list of datacenters this Cassandra cluster belongs to. Data will be replicatedacross these datacenters accordingly. Defaults to [ datacenter1 ].Note: Changing this list alters the underlying Cassandra keyspaces in order to addor remove datacenter replicas accordingly, but replication is NOT made retroactive.You MUST perform aCassandra repairafter adding a new datacenter to realize theadded redundancy. Likewise, you must perform a cleanup to reclaim space if adatacenter is removed. datacenters: - datacenter1Storage GroupsStorage groups are used to map tables to one or more hosts/domains. storage_groups: - name: default.group.local domains: /./