THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
...
API | placeContainer |
Description | Active Container: Stops container process on source-host and starts it for
StandBy Container: Stops container process on source-host and starts it on:
|
Parameters | uuiddeploymentId: unique identifier of a request, populated by the clientapplicationId: unique identifier of the deployed app for which the action is taken processor-id: Samza resource id of container e.g 0, 1, 2 destination-host: valid hostname / “ANY_HOST” / “STANDBY” request-expiry-timeout: [optional]: timeout for any resource request to the cluster manager |
Status code | CREATED, BAD_REQUEST, ACCEPTED, IN_PROGRESS, SUCCEEDED, FAILED |
Returns | Since this is an ASYNC API nothing is returned, UUID for the client to query the status of the request can be queried by processorId |
Failure Scenarios | There are following cases under which a request to place container might fail:
|
...
API | containerStatus |
Description | Gives the status & info of the container placement request, for ex is it running, stopped what control commands are issued on it |
Parameters | processor-id: Samza resource id of container e.g 0, 1, 2 applicationIddeploymentId: unique identifier of the deployed app for which the action is taken uuid: unique identifier of a request |
Status code | BAD_REQUEST |
Returns | Status of the Container placement action |
...
API | controlStandBy |
Description | Starts or Stops a standBy container for the active container |
Parameters | processor-id: Samza resource id of container e.g 0, 1, 2 applicationIddeploymentId: unique identifier of the deployed app for which the action is taken uuid: unique identifier of a request |
Status code | CREATED, BAD_REQUEST, ACCEPTED, IN_PROGRESS, SUCCEEDED, FAILED |
| Returns | UUID for the client to query the status of the request |
Architecture
For implementing a scalable container placement control system, the proposed solution is divided into two parts:
...
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
/**
* Encapsulates the request or response payload information between the ContainerPlacementHandler service and external
* controllers issuing placement actions
*/
public abstract class ContainerPlacementMessage {
public enum StatusCode {
/**
* Indicates that the container placement action is created
*/
CREATED,
/**
* Indicates that the container placement action was rejected because request was deemed invalid
*/
BAD_REQUEST,
/**
* Indicates that the container placement action is accepted and waiting to be processed
*/
ACCEPTED,
/**
* Indicates that the container placement action is in progress
*/
IN_PROGRESS,
/**
* Indicates that the container placement action is in progress
*/
SUCCEEDED,
/**
* Indicates that the container placement action is in failed
*/
FAILED;
}
/**
* UUID attached to a message which helps in identifying duplicate request messages written to metastore and not
* retake actions even if metastore is eventually consistent
*/
protected final UUID uuid;
/**
* Unique identifier for a deployment so messages can be invalidated across a job restarts
* for ex yarn bases cluster manager should set this to app attempt id
*/
protected final String applicationIddeploymentId;
// Logical container Id 0, 1, 2
protected final String processorId;
// Destination host where container is desired to be moved
protected final String destinationHost;
// Optional request expiry which acts as a timeout for any resource request to cluster resource manager
protected final Duration requestExpiry;
// Status of the current request
protected final StatusCode statusCode;
// Timestamp of the request or response message
protected final long timestamp;
protected ContainerPlacementMessage(UUID uuid, String applicationIddeploymentId, String processorId, String destinationHost,
Duration requestExpiry, StatusCode statusCode, long timestamp) {…}
} |
...
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
/**
* Encapsulates the request sent from the external controller to the JobCoordinator to take a container placement action
*/
public class ContainerPlacementRequestMessage extends ContainerPlacementMessage {
public ContainerPlacementRequestMessage(UUID uuid, String applicationIddeploymentId, String processorId, String destinationHost, Duration requestExpiry, long timestamp) {...}
public ContainerPlacementRequestMessage(UUID uuid, String applicationIddeploymentId, String processorId, String destinationHost, long timestamp) {...}
} |
...
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
/**
* Encapsulates the response sent from the JobCoordinator for a container placement action
*/
public class ContainerPlacementResponseMessage extends ContainerPlacementMessage {
// Returned status of the request
private String responseMessage;
public ContainerPlacementResponseMessage(UUID uuid, String applicationIddeploymentId, String processorId, String destinationHost,
Duration requestExpiry, StatusCode statusCode, String responseMessage, long timestamp) {...}
public ContainerPlacementResponseMessage(UUID uuid, String applicationIddeploymentId, String processorId, String destinationHost,
StatusCode statusCode, String responseMessage, long timestamp) {...}
|
...