/**
* Updates the request state and runs the container on the specified host. Assumes a container is
* available on the preferred host, so the caller must verify that before invoking this method.
*
* @param request the {@link SamzaContainerRequest} which is being handled.
* @param preferredHost the preferred host on which the container should be run or {@link
* ContainerRequestState#ANY_HOST} if there is no host preference.
*/
protected void runContainer(SamzaContainerRequest request, String preferredHost) {
// Get the available container
Container container = peekAllocatedContainer(preferredHost);
if (container == null)
throw new SamzaException("Expected container was unavailable on host " + preferredHost);
// Update state
containerRequestState.updateStateAfterAssignment(request, preferredHost, container);
int expectedContainerId = request.expectedContainerId;
// Cancel request and run container
log.info(
"Found available containers on {}. Assigning request for container_id {} with "
+ "timestamp {} to container {}",
new Object[] {
preferredHost,
String.valueOf(expectedContainerId),
request.getRequestTimestamp(),
container.getId()
});
try {
if (preferredHost.equals(ANY_HOST)) {
containerUtil.runContainer(expectedContainerId, container);
} else {
containerUtil.runMatchedContainer(expectedContainerId, container);
}
} catch (SamzaContainerLaunchException e) {
log.warn(
String.format(
"Got exception while starting container %s. Requesting a new container on any host",
container),
e);
containerRequestState.releaseUnstartableContainer(container);
requestContainer(expectedContainerId, ContainerAllocator.ANY_HOST);
}
}
