HTTP Server

The HTTP Server source listens on an HTTP endpoint and processes the contents of all authorized HTTP POST and PUT requests. Use the HTTP Server source to read high volumes of HTTP POST and PUT requests using multiple threads. For information about supported versions, see Supported systems and versions.

The HTTP Server source can read requests containing messages with no compression or with the Gzip or Snappy compression format.

The HTTP Server source can use multiple threads to enable parallel processing of data from multiple HTTP clients. The source can require that requests specify an allowed application ID. Before you run a flow with the source, perform additional steps to configure the HTTP clients.

When a flow stops, the HTTP Server source notes where it stops reading. When the flow starts again, the source continues processing from where it stopped by default. You can reset the offset to process all requested data.

When you configure the HTTP Server source, you specify the maximum number of concurrent requests to determine how many threads to use. You define the listening port, allowed application IDs, and the maximum message size. You can also configure SSL/TLS properties, including default transport protocols and cipher suites.

Tip: Data Collector provides several HTTP sources to address different needs. For a quick comparison chart to help you choose the right one, see Comparing HTTP sources. Also, if processing Flume events as HTTP requests, you will likely find the TCP Server source more efficient.

The source provides request header fields as record header attributes so you can use the information in the flow when needed.

Prerequisites

Before you run a flow with the HTTP Server source, complete the following prerequisites to configure the HTTP clients.

Send data to the listening port

Configure the HTTP clients to send data to the HTTP Server listening port.

When you configure the source, you define a listening port number where the source listens for data. To pass data to the flow, configure each HTTP client to send data to a URL that includes the listening port number.

Note: No other flows or processes can already be bound to the listening port. The listening port can be used only by a single flow.

Use the following format for the URL:

<http | https>://<sdc_hostname>:<listening_port>/

The URL includes the following components:

<http | https> - Use https for secure HTTP connections.
<sdc_hostname> - The Data Collector host name.
<listening_port> - The port number where the source listens for data.

For example: https://localhost:8000/

Include the application ID in requests

For sources configured to require requests from allowed application IDs, configure the HTTP clients to include an allowed application ID in each request.

When you configure the HTTP Server source, you can optionally define a list of application IDs allowed to pass requests to the source. If you specify a list of application IDs, then all messages sent to the source must include one of the specified application IDs.

Client requests can include the application ID in one of the following ways:

In request headers

Add the following information to the request header for all HTTP requests that you want the source to process:

X-SDC-APPLICATION-ID: <application_ID>

For example:

X-SDC-APPLICATION-ID: sdc_http2kafka

In a query parameter in the URL

If you cannot configure the client request headers - for example if the requests are generated by another system - then configure each HTTP client to send data to a URL that includes the application ID in a query parameter.

To include the application ID in a query parameter, enable the Application ID in URL property when you configure the source. Then, include the application ID in a URL query parameter.

Use the following format for the URL:

<http | https>://<sdc_hostname>:<listening_port>/?sdcApplicationId=<application_ID>

The URL includes the following components:

<http | https> - Use https for secure HTTP connections.
<sdc_hostname> - The Data Collector host name.
<listening_port> - The port number where the source listens for data.
<application_ID> - The application ID defined for the HTTP Server source.

For example: https://localhost:8000/?sdcApplicationId=sdc_http2kafka

Multithreaded processing

The HTTP Server source can use multiple threads to perform parallel processing based on the Max Concurrent Requests property.

When you start a multithreaded flow, the source creates the number of threads specified in the Max Concurrent Requests property. Each thread generates a batch from an incoming request and passes the batch to an available flow runner.

A flow runner is a sourceless flow instance - an instance of the flow that includes all of the processors, executors, and targets in the flow and handles all flow processing after the source. Each flow runner processes one batch at a time, just like a flow that runs on a single thread. When the flow of data slows, the flow runners wait idly until they are needed, generating an empty batch at regular intervals. You can configure the Runner Idle Time flow property to specify the interval or to opt out of empty batch generation.

Multithreaded flows preserve the order of records within each batch, just like a single-threaded flow. But since batches are processed by different flow runners, the order that batches are written to targets is not ensured.

For example, say you set the Max Concurrent Requests property to 5. When you start the flow, the source creates five threads, and Data Collector creates a matching number of flow runners. Upon receiving data, the source passes a batch to each of the flow runners for processing. In the batch, HTTP Server includes only the HTTP POST and PUT requests with the specified Application ID.

Each flow runner performs the processing associated with the rest of the flow. After a batch is written to flow targets, the flow runner becomes available for another batch of data. Each batch is processed and written as quickly as possible, independent from other batches processed by other flow runners, so batches may be written differently from the read order.

At any given moment, the five flow runners can each process a batch, so this multithreaded flow processes up to five batches at a time. When incoming data slows, the flow runners sit idle, available for use as soon as the data flow increases.

For more information about multithreaded flows, see Multithreaded flow overview.

Data formats

The HTTP Server source processes data differently based on the data format that you select.

The HTTP Server source processes data formats as follows:

Avro

Generates a record for every Avro record. The source includes the Avro schema in the avroSchema record header attribute. It also includes a precision and scale field attribute for each Decimal field.

The source expects each file to contain the Avro schema and uses the schema to process the Avro data.

The source reads files compressed by Avro-supported compression codecs without requiring additional configuration.

Binary

Generates a record with a single byte array field at the root of the record.

When the data exceeds the user-defined maximum data size, the source cannot process the data. Because the record is not created, the source cannot pass the record to the flow to be written as an error record. Instead, the source generates a stage error.

Datagram

Generates a record for every message. The source can process collectd messages, NetFlow 5 and NetFlow 9 messages, and the following types of syslog messages:

RFC 5424
RFC 3164
Non-standard common messages, such as RFC 3339 dates with no version digit

When processing NetFlow messages, the stage generates different records based on the NetFlow version. When processing NetFlow 9, the records are generated based on the NetFlow 9 configuration properties. For more information, see NetFlow data processing.

Delimited

Generates a record for each delimited line.

The CSV parser that you choose determines the delimiter properties that you configure and how the stage handles parsing errors. You can specify if the data includes a header line and whether to use it. You can define the number of lines to skip before reading, the character set of the data, and the root field type to use for the generated record.

You can also configure the stage to replace a string constant with null values and to ignore control characters.

For more information about reading delimited data, see Reading delimited data.

JSON

Generates a record for each JSON object. You can process JSON files that include multiple JSON objects or a single JSON array.

When an object exceeds the maximum object length defined for the source, the source processes the object based on the error handling configured for the stage.

Protobuf

Generates a record for every protobuf message. By default, the source assumes messages contain multiple protobuf messages.

Protobuf messages must match the specified message type and be described in the descriptor file.

When the data for a record exceeds 1 MB, the source cannot continue processing data in the message. The source handles the message based on the stage error handling property and continues reading the next message.

For information about generating the descriptor file, see Protobuf data format prerequisites.

SDC Record

Generates a record for every record. Use to process records generated by a Data Collector flow using the SDC Record data format.

For error records, the source provides the original record as read from the source in the original flow, as well as error information that you can use to correct the record.

When processing error records, the source expects the error file names and contents as generated by the original flow.

XML

Generates records based on a user-defined delimiter element. Use an XML element directly under the root element or define a simplified XPath expression. If you do not define a delimiter element, the source treats the XML file as a single record.

Generated records include XML attributes and namespace declarations as fields in the record by default. You can configure the stage to include them in the record as field attributes.

You can include XPath information for each parsed XML element and XML attribute in field attributes. This also places each namespace in an xmlns record header attribute.

When a record exceeds the user-defined maximum record length, the source skips the record and continues processing with the next record. It sends the skipped record to the flow for error handling.

Use the XML data format to process valid XML documents. For more information about XML processing, see Reading and processing XML data.

Tip: If you want to process invalid XML documents, you can try using the text data format with custom delimiters. For more information, see Processing XML data with custom delimiters.

Record header attributes

The REST Service source creates record header attributes that include information about the requested URL.

You can use the record:attribute or record:attributeOrDefault functions to access the information in the attributes. For more information about working with record header attributes, see Working with header attributes.

The HTTP Server source creates the following record header attributes:

method - The HTTP method for the request, such as GET, POST, or DELETE.
path - The path of the URL.
queryString - The parameters of the URL that come after the path. Can be empty if there are no query parameters on the URL.
remoteHost - The name of the client or proxy that made the request.

The HTTP Server source also includes HTTP request header fields – such as Host or Content-Type – in records as record header attributes. The attribute names match the original HTTP request header field name.

Configuring an HTTP Server source

About this task

Configure an HTTP Server source to generate multiple threads for parallel processing of HTTP POST and PUT requests.

Procedure

In the Properties panel, on the General tab, configure the following properties:

General Property	Description
Name	Stage name.
Description	Optional description.
On Record Error	Error record handling for the stage: Discard - Discards the record. Send to Error - Sends the record to the flow for error handling. Stop Flow - Stops the flow.

On the HTTP tab, configure the following properties:

HTTP Property	Description
HTTP Listening Port	Listening port for the HTTP Server source. The port number must be included in the URL that the HTTP client uses to pass data. Note: No other flows or processes can already be bound to the listening port. The listening port can be used only by a single flow. For more information, see Send data to the listening port.
List of Application IDs	Optional list of application IDs allowed to pass requests to the HTTP Server source. If specified, then the HTTP client must pass one of the listed IDs, either in the header of the HTTP request or in a query parameter of the URL that the HTTP client uses to pass data. For more information, see Include the application ID in requests. If not specified, then HTTP requests to the source do not require an application ID.
Max Concurrent Requests	Maximum number of HTTP clients allowed to send messages to the source at one time. If the source reaches the configured maximum and receives additional requests from different clients, it processes those requests as slots become available. This property also determines how many threads the source generates and uses for multithreaded processing. For more information, see Multithreaded processing.
Application ID in URL	Enables reading the application ID from the URL. Use when HTTP clients include the application ID in the URL query parameter instead of in the request header. For more information, see Include the application ID in requests.
Max Request Size (MB)	Maximum size of the request body that the source can process.

On the Data Format tab, configure the following property:

Data Format Property	Description
Data Format	Type of data to be processed. Use one of the following data formats: Avro Binary Datagram Delimited JSON Protobuf SDC Record XML

For binary data, on the Data Format tab, configure the following properties:

Binary Property	Description
Compression Format	The compression format of the files: None - Processes only uncompressed files. Compressed File - Processes files compressed by the supported compression formats. Archive - Processes files archived by the supported archive formats. Compressed Archive - Processes files archived and compressed by the supported archive and compression formats.
File Name Pattern within Compressed Directory	For archive and compressed archive files, file name pattern that represents the files to process within the compressed directory. You can use UNIX-style wildcards, such as an asterisk or question mark. For example, .json. Default is , which processes all files.
Max Data Size (bytes)	Maximum number of bytes in the message. Larger messages cannot be processed or written to error.

For datagram data, on the Data Format tab, configure the following properties:

Datagram Properties	Description
Datagram Packet Format	Packet format of the data: collectd NetFlow syslog Raw/separated data
TypesDB File Path	Path to a user-provided types.db file. Overrides the default types.db file. For collectd data only.
Auth File	Path to an optional authentication file. Use an authentication file to accept signed and encrypted data. For collectd data only.
Convert Hi-Res Time & Interval	Converts the collectd high resolution time format interval and timestamp to UNIX time, in milliseconds. For collectd data only.
Exclude Interval	Excludes the interval field from output record. For collectd data only.
Record Generation Mode	Determines the type of values to include in the record. Select one of the following options: Raw Only Interpreted Only Both Raw and Interpreted For NetFlow 9 data only.
Max Templates in Cache	The maximum number of templates to store in the template cache. For more information about templates, see Caching NetFlow 9 templates. Default is -1 for an unlimited cache size. For NetFlow 9 data only.
Template Cache Timeout (ms)	The maximum number of milliseconds to cache an idle template. Templates unused for more than the specified time are evicted from the cache. For more information about templates, see Caching NetFlow 9 templates. Default is -1 for caching templates indefinitely. For NetFlow 9 data only.
Charset	Character encoding of the messages to be processed.
Ignore Control Characters	Removes all ASCII control characters except for the tab, line feed, and carriage return characters.

For delimited data, on the Data Format tab, configure the following properties:

Delimited Property	Description
Header Line	Indicates whether a file contains a header line, and whether to use the header line.
Delimiter Format Type	Delimiter format type. Use one of the following options: Default CSV - File that includes comma-separated values. Ignores empty lines in the file. RFC4180 CSV - Comma-separated file that strictly follows RFC4180 guidelines. MS Excel CSV - Microsoft Excel comma-separated file. MySQL CSV - MySQL comma-separated file. Tab-Separated Values - File that includes tab-separated values. PostgreSQL CSV - PostgreSQL comma-separated file. PostgreSQL Text - PostgreSQL text file. Custom - File that uses user-defined delimiter, escape, and quote characters. Multi Character Delimited - File that uses multiple user-defined characters to delimit fields and lines, and single user-defined escape and quote characters. Available when using the Apache Commons parser type.
Multi Character Field Delimiter	Characters that delimit fields. Default is two pipe characters (\|\|). Available when using the Apache Commons parser with the multi-character delimiter format.
Multi Character Line Delimiter	Characters that delimit lines or records. Default is the newline character (\n). Available when using the Apache Commons parser with the multi-character delimiter format.
Delimiter Character	Delimiter character. Select one of the available options or use Other to enter a custom character. You can enter a Unicode control character using the format `\uNNNN`, where N is a hexadecimal digit from the numbers 0-9 or the letters A-F. For example, enter `\u0000` to use the null character as the delimiter or `\u2028` to use a line separator as the delimiter. Default is the pipe character ( \| ). Available when using the Apache Commons parser with a custom delimiter format.
Field Separator	One or more characters to use as delimiter characters between columns. Available when using the Univocity parser.
Quote Character	Quote character. Available when using the Apache Commons parser with the custom or multi-character delimiter format. Also available when using the Univocity parser.
Allow Comments	Allows commented data to be ignored for custom delimiter format. Available when using the Univocity parser.
Comment Character	Character that marks a comment when comments are enabled for custom delimiter format. Available when using the Univocity parser.
Enable Comments	Allows commented data to be ignored for custom delimiter format. Available when using the Apache Commons parser.
Comment Marker	Character that marks a comment when comments are enabled for custom delimiter format. Available when using the Apache Commons parser.
Lines to Skip	Number of lines to skip before reading data.
Compression Format	The compression format of the files: None - Processes only uncompressed files. Compressed File - Processes files compressed by the supported compression formats. Archive - Processes files archived by the supported archive formats. Compressed Archive - Processes files archived and compressed by the supported archive and compression formats.
File Name Pattern within Compressed Directory	For archive and compressed archive files, file name pattern that represents the files to process within the compressed directory. You can use UNIX-style wildcards, such as an asterisk or question mark. For example, .json. Default is , which processes all files.
CSV Parser	Parser to use to process delimited data: Apache Commons - Provides robust parsing and a wide range of delimited format types. Univocity - Can provide faster processing for wide delimited files, such as those with over 200 columns. Default is Apache Commons.
Max Columns	Maximum number of columns to process per record. Available when using the Univocity parser.
Max Character per Column	Maximum number of characters to process in each column. Available when using the Univocity parser.
Skip Empty Lines	Allows skipping empty lines. Available when using the Univocity parser.
Allow Extra Columns	Allows processing records with more columns than exist in the header line. Available when using the Apache Commons parser to process data with a header line.
Extra Column Prefix	Prefix to use for any additional columns. Extra columns are named using the prefix and sequential increasing integers as follows: `<prefix><integer>`. For example, `_extra_1`. Default is `_extra_`. Available when using the Apache Commons parser to process data with a header line while allowing extra columns.
Max Record Length (chars)	Maximum length of a record in characters. Longer records are not read. This property can be limited by the Data Collector parser buffer size. For more information, see Maximum record size. Available when using the Apache Commons parser.
Ignore Empty Lines	Allows empty lines to be ignored. Available when using the Apache Commons parser with the custom delimiter format.
Root Field Type	Root field type to use: List-Map - Generates an indexed list of data. Enables you to use standard functions to process data. Use for new flows. List - Generates a record with an indexed list with a map for header and value. Requires the use of delimited data functions to process data. Use only to maintain flows created before 1.1.0.
Parse NULLs	Replaces the specified string constant with null values.
NULL Constant	String constant to replace with null values.
Charset	Character encoding of the files to be processed.
Ignore Control Characters	Removes all ASCII control characters except for the tab, line feed, and carriage return characters.

For JSON data, on the Data Format tab, configure the following properties:

JSON Property	Description
JSON Content	Type of JSON content. Use one of the following options: Array of Objects Multiple Objects
Compression Format	The compression format of the files: None - Processes only uncompressed files. Compressed File - Processes files compressed by the supported compression formats. Archive - Processes files archived by the supported archive formats. Compressed Archive - Processes files archived and compressed by the supported archive and compression formats.
File Name Pattern within Compressed Directory	For archive and compressed archive files, file name pattern that represents the files to process within the compressed directory. You can use UNIX-style wildcards, such as an asterisk or question mark. For example, .json. Default is , which processes all files.
Maximum Object Length (chars)	Maximum number of characters in a JSON object. Longer objects are diverted to the flow for error handling. This property can be limited by the Data Collector parser buffer size. For more information, see Maximum record size.
Charset	Character encoding of the files to be processed.
Ignore Control Characters	Removes all ASCII control characters except for the tab, line feed, and carriage return characters.

For protobuf data, on the Data Format tab, configure the following properties:

Protobuf Property	Description
Protobuf Descriptor File	Descriptor file (.desc) to use. The descriptor file must be in the Data Collector resources directory, `$SDC_RESOURCES`. For information about generating the descriptor file, see Protobuf data format prerequisites.
Message Type	The fully-qualified name for the message type to use when reading data. Use the following format: `<package name>.<message type>`. Use a message type defined in the descriptor file.
Delimited Messages	Indicates if a message might include more than one protobuf message.
Compression Format	The compression format of the files: None - Processes only uncompressed files. Compressed File - Processes files that are compressed by the supported compression formats. Archive - Processes files that are archived by the supported archive formats. Compressed Archive - Processes files that are archived and compressed by the supported archive and compression formats.
File Name Pattern within Compressed Directory	For archive and compressed archive files, file name pattern that represents the files to process within the compressed directory. You can use UNIX-style wildcards, such as an asterisk or question mark. For example, .json. Default is , which processes all files.

For SDC Record data, on the Data Format tab, configure the following properties:

SDC Record Property	Description
Compression Format	The compression format of the files: None - Processes only uncompressed files. Compressed File - Processes files compressed by the supported compression formats. Archive - Processes files archived by the supported archive formats. Compressed Archive - Processes files archived and compressed by the supported archive and compression formats.
File Name Pattern within Compressed Directory	For archive and compressed archive files, file name pattern that represents the files to process within the compressed directory. You can use UNIX-style wildcards, such as an asterisk or question mark. For example, .json. Default is , which processes all files.

For XML data, on the Data Format tab, configure the following properties:

XML Property	Description
Delimiter Element	Delimiter to use to generate records. Omit a delimiter to treat the entire XML document as one record. Use one of the following: An XML element directly under the root element. Use the XML element name without surrounding angle brackets ( < > ) . For example, msg instead of <msg>. A simplified XPath expression that specifies the data to use. Use a simplified XPath expression to access data deeper in the XML document or data that requires a more complex access method. For more information about valid syntax, see Simplified XPath syntax.
Compression Format	The compression format of the files: None - Processes only uncompressed files. Compressed File - Processes files that are compressed by the supported compression formats. Archive - Processes files that are archived by the supported archive formats. Compressed Archive - Processes files that are archived and compressed by the supported archive and compression formats.
File Name Pattern within Compressed Directory	For archive and compressed archive files, file name pattern that represents the files to process within the compressed directory. You can use UNIX-style wildcards, such as an asterisk or question mark. For example, .json. Default is , which processes all files.
Preserve Root Element	Includes the root element in the generated records. When omitting a delimiter to generate a single record, the root element is the root element of the XML document. When specifying a delimiter to generate multiple records, the root element is the XML element specified as the delimiter element or is the last XML element in the simplified XPath expression specified as the delimiter element.
Include Field XPaths	Includes the XPath to each parsed XML element and XML attribute in field attributes. Also includes each namespace in an xmlns record header attribute. When not selected, this information is not included in the record. By default, the property is not selected.
Namespaces	Namespace prefix and URI to use when parsing the XML document. Define namespaces when the XML element being used includes a namespace prefix or when the XPath expression includes namespaces. For information about using namespaces with an XML element, see Using XML elements with namespaces. For information about using namespaces with XPath expressions, see Using XPath expressions with namespaces. Using simple or bulk edit mode, click the Add icon to add additional namespaces.
Output Field Attributes	Includes XML attributes and namespace declarations in the record as field attributes. When not selected, XML attributes and namespace declarations are included in the record as fields. By default, the property is not selected.
Max Record Length (chars)	The maximum number of characters in a record. Longer records are diverted to the flow for error handling. This property can be limited by the Data Collector parser buffer size. For more information, see Maximum record size.
Charset	Character encoding of the files to be processed.
Ignore Control Characters	Removes all ASCII control characters except for the tab, line feed, and carriage return characters.

To use SSL/TLS, click the TLS tab and configure the following properties:

TLS Property	Description
Use TLS	Enables the use of TLS.
Use Remote Keystore	Enables loading the contents of the keystore from a remote credential store or from values entered in the stage properties. For more information, see Remote keystore and truststore.
Private Key	Private key used in the remote keystore. Enter a credential function that returns the key or enter the contents of the key.
Certificate Chain	Each PEM certificate used in the remote keystore. Enter a credential function that returns the certificate or enter the contents of the certificate. Using simple or bulk edit mode, click the Add icon to add additional certificates.
Keystore File	Path to the local keystore file. Enter an absolute path to the file or enter the following expression to define the file stored in the Data Collector resources directory: `${runtime:resourcesDirPath()}/keystore.jks` By default, no keystore is used.
Keystore Type	Type of keystore to use. Use one of the following types: Java Keystore File (JKS) PKCS #12 (p12 file) Default is Java Keystore File (JKS).
Keystore Password	Password to the keystore file. A password is optional, but recommended. Tip: To secure sensitive information such as passwords, you can use runtime resources or credential stores.
Keystore Key Algorithm	Algorithm to manage the keystore. Default is SunX509.
Use Default Protocols	Uses the default TLSv1.2 transport layer security (TLS) protocol. To use a different protocol, clear this option.
Transport Protocols	TLS protocols to use. To use a protocol other than the default TLSv1.2, click the Add icon and enter the protocol name. You can use simple or bulk edit mode to add protocols. Note: Older protocols are not as secure as TLSv1.2.
Use Default Cipher Suites	Uses a default cipher suite for the SSL/TLS handshake. To use a different cipher suite, clear this option.
Cipher Suites	Cipher suites to use. To use a cipher suite that is not a part of the default set, click the Add icon and enter the name of the cipher suite. You can use simple or bulk edit mode to add cipher suites. Enter the Java Secure Socket Extension (JSSE) name for the additional cipher suites that you want to use.