Configuring External Stream Sinks

External Stream sinks make use of s-Server’s Extensible Common Data framework. This framework allows you to read and write rows of data in a range of forms over a range of input/output formats, including the file system, network sockets, AMQP, Amazon Kinesis, and Kafka. All data is sent as a string in CSV, XML, or JSON format

Using the File System as a External Stream Sink

To read streaming data over the file system, you need two pieces of information: - The directory in which the file resides. - A pattern for the file’s name. Here, you enter part of the file’s name, such as output, csv, or log. No quotation marks are necessary.

| DIRECTORY | Directory in which file resides. |

Using a Network Socket as a External Stream Sink

To read from a line, CSV, XML, or JSON file over a network socket, you need to configure the socket connection. You may want to consult with whoever has set up the application with which StreamLab will connect over the socket. Network sockets initiate a connection over TCP or UDP. Connections can be initiated by remote applications or by StreamLab itself. To tell StreamLab listen to a remote host, use the Remote Host and Remote Port fields. Connections can optionally be made using IPV6.

Name Description
Remote Host Hostname to send rows to or receive rows from. You can override this to ‘LOCALHOST’ to listen to only local connections, or a specific ip address, such as <168.212.226.204>.
Socket uses TCP? Whether the socket uses TCP (True) or UDP (False). Default is false (UDP).
Skip Header True or false; defaults to false. Specifies if the parser should skip the first row of input files. Usually, you would do this if the first row of data contains column headers.

Using MongoDB as a External Stream Sink

Options for Writing to a MongoDB Collection

Option Definition
URL Fully qualified URL starting with *mongodb:// and including, at minimum, a host name (or IP address or UNIX domain socket). URL can also include a username and password (these are passed to the MongoDB instance) and a port number. See https://docs.mongodb.com/manual/reference/connection-string/ for more information.

Using AMQP as a External Stream Sink

To read from a External Stream sink over AMQP, you need to configure the AMQP connection. AMQP stands for Advanced Message Queuing Protocol, and is an Open Standard for Messaging Middleware. For more information, see http://www.amqp.org/about/what. You may want to consult with whoever has set up AMQP in your environment.

AMQP 0.9.1 vs 1.0

There are distinct differences between the way AMQP up to 0.9.1 works and the way AMQP 1.0 works. Roughly, AMQP 1.0 only provides network wire-level protocol for the exchange of messages, while up to 0.9.1, AMQP employed a system of exchanges, queues and bindings to exchange messages. As a result of this change, you configure StreamLab for AMQP differently for 1.0 than for up to 0.9.1

| Name | Description | | — | — | | AMQP URL | Required. Connection URL for AMQP legacy server. This includes the server’s hostname, user, password, port and so on. This will differ depending on whether you are using AMQP 1.0 or a legacy version. |

AMQP_LEGACY (AMQP protocol Version 0.9, e.g., RabbitMQ)

Format:

amqp://<username>:<password>@<clientid>/<profile>?brokerlist='tcp://<hostname>:<portNumber>'&[ <optionsList> ]

Example:

amqp://guest:guest@clientid/default?brokerlist='tcp://localhost:5672'

AMQP10 (AMQP protocol Version 1.0) - connectionfactory.localhost:

Format:

amqp://<username>:<password>@<hostname>:<portNumber>?<optionsList>'

Example:

amqp://guest:guest@localhost:5672?clientid=test-client&remote-host=default

Single quotes must be doubled for SQL formatting. You may need to do additional URL escaping depending on your AMQP implementation.Single quotes must be doubled for SQL formatting. You may need to do additional URL escaping depending on your AMQP implementation. The site https://azure.microsoft.com/en-us/documentation/articles/service-bus-java-how-to-use-jms-api-amqp/ offers an example of formatting a connection URL.|

Option Name Description
Partition Expression You should only use this if DESTINATION includes “{PARTITION}”. This should be a dk.brics regular expression, such as *<0-3>.
Acknowledge Mode Optional. Acknowledgment mode that ECDA communicates to the AMQP 1.0 server. Options are AUTO, MANUAL, or NONE; defaults to AUTO. Details on these modes are available at http://docs.spring.io/spring-integration/reference/html/amqp.html# amqp-inbound-ack

Roughly, AUTO asks the container on the AMQP server to acknowledge once message is completely delivered. MANUAL means that delivery tags and channels are provided in message headers, and NONE means no acknowledgments.

Using Amazon Kinesis as a External Stream sink

To read from a External Stream sink over Amazon Kinesis, you need to configure the Amazon Kinesis connection. | Option Name | Description | | — | — | | Kinesis Stream Name | Required. Name of Kinesis stream to write to. No default.| | Kinesis Application Name | Identifies client in cloud watch (defaults to sqlstream). | | . Must point to a credential file on the s-Server file system with the following format: ```sql [default] aws_access_key_id = xxx aws_secret_access_key = yyy

This defaults to blank, which goes to *~/.aws/credentials.

You need to have an AWS profile set up, and a configuration file stored on your system, in order to read from or write to Kinesis. See - Setting Up an AWS Profile Path in the topic - Reading from Kinesis Streams in the SQLstream Integration Guide .

| AWS Profile Name | Optional. Profile name to use within credentials file. Defaults to *default.| | Initial Position | LATEST for latest or TRIM_HORIZON for earliest. Defaults to LATEST.| | Socket Timeout | (defaults to -1) if set will override kinesis socket timeout | |

Using Kafka as a External Stream Sink

To read from a line, CSV, XML, or JSON file over Kafka, you need to configure the connection to Kafka. Kafka is an open-source, real-time publish-subscribe messaging framework. See http://kafka.apache.org/ for more details. You may want to consult with whoever has set up the Kafka messaging system in your environment. To connect with Kafka, you need two pieces of information: - The name and port of the Kafka broker (this defaults to localhost:9092, but the source will not work if a Kafka broker is not working at this location). - The Kafka topic name from which you are reading.

The other configuration details below help manage the starting point for reading Kafka topics as well as the amount of data fed to StreamLab. | Format Name | Name | | — | — | Name/Port | hostname:port of the Kafka broker. Defaults to localhost:9092. Used for getting metadata (topics, partitions and replicas). Actual socket connections are established using the information from this metadata. Use commas to separate multiple brokers. | | Topic Required. Kafka Topic | | Starting Time The time to start reading from specified topic. Options are LATEST, EARLIEST, or a long int representing a timestamp (milliseconds since epoch). Defaults to LATEST. | | Starting Offset When to start reading from (Default is -1) as a long int representing a timestamp (milliseconds since epoch) | | Partition Number of Kafka partition to read from. Defaults to 0. | | Buffer Size Buffer size in bytes. Defaults to 1048576. | | Fetch Size Fetch size. Defaults to 100000.