Glossary

Component

Components in the Carbon platform add functionality to all WSO2 Carbon-based products. For example, the statistics component enables users to monitor system and service level statistics. A component in the Carbon platform is made up of one or more OSGi bundles, which is the modularization unit in OSGi similar to a JAR file in Java. For example, the statistics component contains two bundles: one is the back-end bundle that collects, summarizes, and stores statistics, and the other is the front-end bundle, which presents the data to the user through a user-friendly interface. This component-based architecture of the WSO2 Carbon platform gives developers flexibility to build efficient and lean products that best suit their unique business needs simply by adding and removing components.

Data Access Layer

The data access layer persists the data processed by WSO2 DAS and consists of two components named Analytics Record Store and Analytics File System.

The Analytics Record Store handles the storage of records that are received by WSO2 DAS in the form of events. The Analytics File System handles the storage of index data.

Latency

The time taken by the event flow to process a single event. A lower latency indicates better performance in terms of the efficiency with which the events are processed. Latency is affected by the receiver/publisher adapter type used as well as the performance configurations (see Performance Tuning for further information). Reducing latency may involve achieving a lower throughput because the load handled by an event flow may need to be reduced in order to increase the event processing speed.

Port offset

The port offset feature allows you to run multiple WSO2 products, multiple instances of a WSO2 product, or multiple WSO2 product clusters on the same server or virtual machine (VM). The port offset defines the number by which all ports defined in the runtime such as the HTTP/S ports will be offset. For example, if the HTTP port is defined as 9763 and the portOffset is 1, the effective HTTP port will be 9764. Therefore, for each additional WSO2 product, instance, or cluster you add to a server, set the port offset to a unique value (the default is 0).

Port offset can be passed to the server during startup as follows:
./wso2server.sh -DportOffset=3

Alternatively, you can set it in the Ports section of <PRODUCT_HOME>/repository/conf/carbon.xml as follows:
<Offset>3</Offset>

Important

The tool boxes that come with samples use an embedded H2 database to persist summarized data. They only work with the default DAS installation. If you change the default settings (e.g., port offset values, H2 database settings), you should also change the corresponding Hive scripts.

For example, the Hive script associated with the default KPI Monitoring sample has Cassandra port set as 9160. If you change the port offset, you should manually change the Cassandra port too, by following these steps:

After installing the tool box, log in to the management console, select List sub menu under Analytics menu. This will open the Available Scripts window.
Set "cassandra.port" = "9161" in the phone_retail_store_script and Save.

Shard

All indexing related data are partitioned into units known as shards. these shards can be viewed in the <DAS_HOME>/repository/data/index_data directory where there is a sub directory for each available shard.

SOAP

An XML-based, extensible message envelope format, with "bindings" to underlying protocols. The primary protocols are HTTP and HTTPS, although bindings for others, including SMTP and XMPP, have been written.

Throughput

The number of events handled by an event flow per second. A higher throughput indicates better performance in terms of event processing capacity of the DAS server. The throughput is affected by the performance configurations (see Performance Tuning for further information). Increasing the throughput may involve increasing the latency because an increased load of events handled by an event flow can reduce the event processing speed.

WSO2 DAS Management Console

WSO2 DAS Management Console is a Web based control panel powered by JSP and AJAX which enables system administrators to interact with a running the DAS instance without touching any underlying configuration files. The Management Console allows the users to command and control proxy services, sequences, transports, local entries, registry, modules, endpoints and much more.