Parameters: lease - Number of units in the lease period unit - Time unit of the lease period countLimit - maximum number of tasks to lease Returns: A list of TaskHandle for each leased task. If you generate more than 10 LeaseTasks requests per second, only the first 10 requests This method supports leasing a maximum of 1000 tasks for no more than one You must call deleteTask to prevent the task from being leased again after It is guaranteed that the leased tasks will be unavailable for lease to others in Queue having the earliest eta such that eta is prior to the time at which the lease is If fewer tasks than countLimit are available, allĪvailable tasks in this Queue will be returned. Leases up to countLimit tasks from this queue for a period specified by InvalidQueueModeException - task method is and queue is UnsupportedTranslationException - If chosen character encoding is unsupported. TransientFailureException - Attempting the request after this exception may succeed. That if a TaskAlreadyExistsException is caught, the caller can be guaranteed that forĮach one of the provided TaskOptions, either the corresponding task was successfullyĪdded, or a task with the given name was successfully added in the past. Of a task that was previously created, and if no other Exception would be thrown.

(see queue.xml) TaskAlreadyExistsException - If any of the provided TaskOptions contained a name Throws: InternalFailureException - If the queue does not exist. Returns: A list containing a TaskHandle for each added task. Parameters: taskOptions - An iterable over task definitions. if this method throws then some tasks may have been added to Once again changed to pull, these tasks will eventually be available for Will fail on auto-execution because they lack a url. When switching from pull to push, existing tasks will remain in the queue but Push to pull, tasks will stay in the task queue and are available for lease,īut url and headers information will be ignored when returning the tasks. Queue mode can be switched between push and pull. If deleteTask is not called before the leaseĮxpires, the task will again be available for lease. Has finished processing a task that is leased, it should callĭeleteTask(String). Attempting to callĪ InvalidQueueModeException to be thrown. Pull mode queues do not automatically deliver tasks to the application. The tasks in push queues must be added with one of However, only tasks with mayīe added to pull queues. Queues may be configured in either push or pull mode, but they share the In other words, when the transactionĬommits you are guaranteed that your task will be added and run, not that

Participate in an existing transaction, the execution of the task cannot Note that while the addition of the task to the queue can Independently of an existing datastore transaction you can invokeĪdd(Transaction, TaskOptions) with a null transactionĪrgument. You want to add a task to a queue and have that operation succeed or fail If a datastore transaction is in progress whenĪdd() or add(TaskOptions) is invoked, the task will onlyīe added to the queue if the datastore transaction successfully commits. Implementations of this interface must be threadsafe.

Queue java api