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ciao-docs-finalizer

CIP to detect completion of a document upload and handle any finalization

Introduction

The purpose of this CIP is to monitor an in-progress folder which contains events associated with a document upload (typically originating from ciao-docs-parser). The CIP maintains an internal state machine for each document upload, and once completion is detected (success or otherwise) a configurable action is performed.

ciao-docs-finalizer is built on top of Apache Camel and Spring Framework, and can be run as a stand-alone Java application, or via Docker.

Each application hosts a Camel route, following the structure:

input folder (event files) -> state-machine transition -> (on completion): run action

The details of the monitored folder and completion actions are specified at runtime through a combination of ciao-configuration properties and Spring XML files.

Supported completion actions:

  • MoveToCompletedFolder - Moves the document's directory to the folder specified in the ./control/completed-folder file
  • MoveToErrorFolder - Moves the document's directory to the folder specified in the ./control/error-folder file

For more advanced usages, a custom action can be integrated by implementing the TransitionListener Java interface and providing a suitable spring XML configuration on the classpath.

In-progress Folder:

The event files use a common naming format written by the CIPs involved in a document upload process. The contents and format of the event files is determined by the component writing the event and is not interpreted by this CIP.

  • A detailed description of the in-progress folder and associated state machine is available in docs/state-machine.md.

Configuration

For further details of how ciao-configuration and Spring XML interact, please see ciao-core.

Spring XML

On application start-up, a series of Spring Framework XML files are used to construct the core application objects. The created objects include the main Camel context, input/output components, routes and any intermediate processors.

The configuration is split into multiple XML files, each covering a separate area of the application. These files are selectively included at runtime via CIAO properties, allowing alternative technologies and/or implementations to be chosen. Each imported XML file can support a different set of CIAO properties.

The Spring XML files are loaded from the classpath under the META-INF/spring package.

Core:

  • beans.xml - The main configuration responsible for initialising properties, importing additional resources and starting Camel.

Repositories:

An `IdempotentRepository' is configured to enable [multiple consumers](http://camel.apache.org competing-consumers.html) access the same folder concurrently.

  • 'repository/memory.xml' - An in-memory implementation suitable for use when there is only a single consumer, or multiple-consumers are all contained within the same JVM instance.
  • 'repository/hazelcast.xml' - A grid-based implementation backed by Hazelcast. The component is hosted entirely within the JVM process and uses a combination of multicast and point-to-point networking to maintain a cross-server data grid.

Processors:

  • processors/default.xml - Creates a file poller for the in-progress folder and an associated state-machine to handle detected event transitions.

Messaging:

  • messaging/activemq.xml - Configures ActiveMQ as the JMS implementation for input/output queues.
  • messaging/activemq-embedded.xml - Configures an internal embedded ActiveMQ as the JMS implementation for input/output queues. (For use during development/testing)

CIAO Properties

At runtime ciao-docs-finalizer uses the available CIAO properties to determine which Spring XML files to load, which Camel routes to create, and how individual routes and components should be wired.

Camel Logging:

Spring Configuration:

  • repositoryConfig - Selects which repository configuration to load: repositories/${repositoryConfig}.xml

  • processorConfig - Selects which processor configuration to load: processors/${processorConfig}.xml

  • messagingConfig - Selects which messaging configuration to load: messaging/${messagingConfig}.xml

Route Configuration:

  • inProgressFolderPollPeriod - Time in millis between polling attempts on the in-progress folder.
  • inProgressFolder - The folder to monitor for document upload progress events.
  • documentPreparationTimeout - Maximum time in millis to wait for a document to complete the preparation stage (prior to sending) before raising a timeout event.
  • documentSendTimeout - Maximum time in millis to wait for confirmation that the document has been sent before raising a timeout event.
  • infResponseTimeout - Maximum time in millis to wait for an infrastructure response before raising a timeout event.
  • busResponseTimeout - Maximum time in millis to wait for a business response before raising a timeout event.
  • idempotentActions - Boolean flag which selects if an idempotent checks should be performed before performing state transition actions. This is used to ensure that only one node in a cluster performs the action.
  • actions - Specifies which action to perform when a document upload transitions to a particular state. The format is one mapping per line, where a mapping has the form: to={EVENT_NAME} > {ACTION_NAME}.

Hazelcast Configuration:

The following properties are applicable for repositoryConfig=hazelcast:

  • hazelcast.group.name - Name of the hazelcast cluster group
  • hazelcast.group.password - Password of the hazelcast cluster group
  • hazelcast.network.port - The network port to use for the hazelcast server - if the port is already in use it will be incremented until a free port is found
  • hazelcast.network.publicAddress - The (optional) public address of the hazelcast node - this can be used if nodes need to communicate over NAT.
  • hazelcast.network.join.tcp_ip - Comma separated list of static cluster members - if empty, multicast join should be enabled
  • hazelcast.network.join.multicast.enabled - Boolean value specifying whether multicast join should be used to find cluster members - if false, static TCP-IP members should be specified
  • hazelcast.network.join.multicast.group - Multicast address to use for finding cluster members
  • hazelcast.network.join.multicast.port - Multicast port to use for finding cluster members

Default Processor​:

The default processor configuration does not currently support any additional properties.

Example

# Camel logging
camel.log.mdc=true
camel.log.trace=false
camel.log.debugStreams=false

# Select which processor config to use (via dynamic spring imports)
processorConfig=default

# Select which idempotent repository config to use (via dynamic spring imports)
repositoryConfig=hazelcast
# repositoryConfig=memory

# Hazelcast settings (if repositoryConfig=hazelcast)
hazelcast.group.name=ciao-docs-finalizer
hazelcast.group.password=ciao-docs-finalizer-pass
hazelcast.network.port=5701
hazelcast.network.publicAddress=
hazelcast.network.join.tcp_ip.members=
hazelcast.network.join.multicast.enabled=true
hazelcast.network.join.multicast.group=224.2.2.3
hazelcast.network.join.multicast.port=54327

inProgressFolderPollPeriod=5000
inProgressFolder=./in-progress

documentPreparationTimeout=60000
documentSendTimeout=180000
infResponseTimeout=300000
busResponseTimeout=17280000

idempotentActions=true
actions=\
	to=SUCCEEDED > MoveToCompletedFolder	\n\
	to=FAILED > MoveToErrorFolder

Building and Running

To pull down the code, run:

git clone https://github.com/nhs-ciao/ciao-docs-finalizer.git

You can then compile the module via:

mvn clean install -P bin-archive

This will compile a number of related modules - the main CIP module is ciao-docs-finalizer, and the full binary archive (with dependencies) can be found at target\ciao-docs-finalizer-{version}-bin.zip. To run the CIP, unpack this zip to a directory of your choosing and follow the instructions in the README.txt.

The CIP requires access to various file system directories and network ports (dependent on the selected configuration):

etcd:

  • Connects to: localhost:2379

ActiveMQ:

  • Connects to: localhost:61616

Hazelcast:

  • Multicast discovery: 224.2.2.3:54327 (If enabled)
  • Listens on: *:5701 (If port is already taken, the port number is incremented until a free port is found)
  • Connects to clustered nodes defined by the hazelcast.network.join.tcp_ip.members property

Filesystem:

  • If etcd is not available, CIAO properties will be loaded from: ~/.ciao/
  • The CIP will monitor event files in the folder specified by the inProgressFolder property.