ganeti.jqueue.JobQueue

class documentation

class JobQueue(object):

Queue used to manage the jobs.

Class Method	`SubmitManyJobs`	Create and store multiple jobs.
Method	`__init__`	Constructor for JobQueue.
Method	`CancelJob`	Cancels a job.
Method	`ChangeJobPriority`	Changes a job's priority.
Method	`HasJobBeenFinalized`	Checks if a job has been finalized.
Method	`SafeLoadJobFromDisk`	Load the given job file from disk.
Method	`UpdateJobUnlocked`	Update a job's on disk storage.
Instance Variable	`context`	Undocumented
Instance Variable	`depmgr`	Undocumented
Class Method	`_GetJobIDsUnlocked`	Return all known job IDs.
Static Method	`_CheckRpcResult`	Verifies the status of an RPC call.
Static Method	`_DetermineJobDirectories`	Build list of directories containing job files.
Static Method	`_GetArchivedJobPath`	Returns the archived job file for a give job id.
Static Method	`_GetJobPath`	Returns the job file for a given job id.
Static Method	`_ResolveJobDependencies`	Resolves relative job IDs in dependencies.
Method	`_GetJobStatusForDependencies`	Gets the status of a job for dependencies.
Method	`_GetNodeIp`	Helper for returning the node name/ip list.
Method	`_GetRpc`	Gets RPC runner with context.
Method	`_LoadJobFromDisk`	Load the given job file from disk.
Method	`_LoadJobUnlocked`	Loads a job from the disk or memory.
Method	`_ModifyJobUnlocked`	Modifies a job.
Method	`_RenameFilesUnlocked`	Renames a file locally and then replicate the change.
Method	`_UpdateJobQueueFile`	Writes a file locally and then replicates it to all nodes.
Instance Variable	`_memcache`	Undocumented
Instance Variable	`_my_hostname`	Undocumented
Instance Variable	`_nodes`	Undocumented

@classmethod
def SubmitManyJobs(cls, jobs): ¶

Create and store multiple jobs.

def __init__(self, context, cfg): ¶

Constructor for JobQueue.

The constructor will initialize the job queue object and then start loading the current jobs from disk, either for starting them (if they were queue) or for aborting them (if they were already running).

Parameters
context:GanetiContext	the context object for access to the configuration data and other ganeti objects
cfg	Undocumented

def CancelJob(self, job_id): ¶

Cancels a job.

This will only succeed if the job has not started yet.

Parameters
job_id:int	job ID of job to be cancelled.

def ChangeJobPriority(self, job_id, priority): ¶

Changes a job's priority.

Parameters
job_id:int	ID of the job whose priority should be changed
priority:int	New priority

def HasJobBeenFinalized(self, job_id): ¶

Checks if a job has been finalized.

Parameters
job_id:int	Job identifier
Returns
boolean	True if the job has been finalized, False if the timeout has been reached, None if the job doesn't exist

def SafeLoadJobFromDisk(self, job_id, try_archived, writable=None): ¶

Load the given job file from disk.

Given a job file, read, load and restore it in a _QueuedJob format. In case of error reading the job, it gets returned as None, and the exception is logged.

Parameters
job_id:int	job identifier
try_archived:bool	Whether to try loading an archived job
writable	Undocumented
Returns
`_QueuedJob` or None	either None or the job object

def UpdateJobUnlocked(self, job, replicate=True): ¶

Update a job's on disk storage.

After a job has been modified, this function needs to be called in order to write the changes to disk and replicate them to the other nodes.

Parameters
job:`_QueuedJob`	the changed job
replicate:boolean	whether to replicate the change to remote nodes

context = ¶

Undocumented

depmgr = ¶

Undocumented

@classmethod
def _GetJobIDsUnlocked(cls, sort=True, archived=False): ¶

Return all known job IDs.

The method only looks at disk because it's a requirement that all jobs are present on disk (so in the _memcache we don't have any extra IDs).

Parameters
sort:boolean	perform sorting on the returned job ids
archived	Undocumented
Returns
list	the list of job IDs

@staticmethod
def _CheckRpcResult(result, nodes, failmsg): ¶

Verifies the status of an RPC call.

Since we aim to keep consistency should this node (the current master) fail, we will log errors if our rpc fail, and especially log the case when more than half of the nodes fails.

Parameters
result	the data as returned from the rpc call
nodes:list	the list of nodes we made the call to
failmsg:str	the identifier to be used for logging

@staticmethod
def _DetermineJobDirectories(archived): ¶

Build list of directories containing job files.

Parameters
archived:bool	Whether to include directories for archived jobs
Returns
list	Undocumented

@staticmethod
def _GetArchivedJobPath(job_id): ¶

Returns the archived job file for a give job id.

Parameters
job_id:str	the job identifier
Returns
str	the path to the archived job file

@staticmethod
def _GetJobPath(job_id): ¶

Returns the job file for a given job id.

Parameters
job_id:str	the job identifier
Returns
str	the path to the job file

@staticmethod
def _ResolveJobDependencies(resolve_fn, deps): ¶

Resolves relative job IDs in dependencies.

Parameters
resolve_fn:callable	Function to resolve a relative job ID
deps:list	Dependencies
Returns
tuple; (boolean, string or list)	If successful (first tuple item), the returned list contains resolved job IDs along with the requested status; if not successful, the second element is an error message

def _GetJobStatusForDependencies(self, job_id): ¶

Gets the status of a job for dependencies.

Parameters
job_id:int	Job ID
Raises
`errors.JobLost`	If job can't be found

def _GetNodeIp(self): ¶

Helper for returning the node name/ip list.

Returns
(list, list)	a tuple of two lists, the first one with the node names and the second one with the node addresses

def _GetRpc(self, address_list): ¶

Gets RPC runner with context.

def _LoadJobFromDisk(self, job_id, try_archived, writable=None): ¶

Load the given job file from disk.

Given a job file, read, load and restore it in a _QueuedJob format.

Parameters
job_id:int	job identifier
try_archived:bool	Whether to try loading an archived job
writable	Undocumented
Returns
`_QueuedJob` or None	either None or the job object

def _LoadJobUnlocked(self, job_id): ¶

Loads a job from the disk or memory.

Given a job id, this will return the cached job object if existing, or try to load the job from the disk. If loading from disk, it will also add the job to the cache.

Parameters
job_id:int	the job id
Returns
`_QueuedJob` or None	either None or the job object

def _ModifyJobUnlocked(self, job_id, mod_fn): ¶

Modifies a job.

Parameters
job_id:int	Job ID
mod_fn:callable	Modifying function, receiving job object as parameter, returning tuple of (status boolean, message string)

def _RenameFilesUnlocked(self, rename): ¶

Renames a file locally and then replicate the change.

This function will rename a file in the local queue directory and then replicate this rename to all the other nodes we have.

Parameters
rename:list of (old, new)	List containing tuples mapping old to new names

def _UpdateJobQueueFile(self, file_name, data, replicate): ¶

Writes a file locally and then replicates it to all nodes.

This function will replace the contents of a file on the local node and then replicate it to all the other nodes we have.

Parameters
file_name:str	the path of the file to be replicated
data:str	the new contents of the file
replicate:boolean	whether to spread the changes to the remote nodes

_memcache = ¶

Undocumented

_my_hostname = ¶

Undocumented

_nodes = ¶

Undocumented