org.apache.slider.server.appmaster.state

Class NodeInstance

java.lang.Object

org.apache.slider.server.appmaster.state.NodeInstance

public class NodeInstance
extends Object

A node instance -stores information about a node in the cluster.

Operations on the array/set of roles are synchronized.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NodeInstance.CompareNames A comparator for sorting entries alphabetically
static class	NodeInstance.MoreActiveThan A comparator for sorting entries where the role is newer than the other.
static class	NodeInstance.Preferred A comparator for sorting entries where the node is preferred over another.

Field Summary

Fields

Modifier and Type	Field and Description
String	hostname

Constructor Summary

Constructors

Constructor and Description
NodeInstance(String hostname, int roles) Create an instance and the (empty) array of nodes

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canHost(int role, String label) Is this node instance a suitable candidate for the specific role?
boolean	equals(Object o) Equality test is purely on the hostname of the node address
boolean	exceedsFailureThreshold(RoleStatus role) Predicate to query if the number of recent failures of a role on this node exceeds that role's failure threshold.
NodeEntry	get(int role) Get the entry for a role -if present
int	getActiveRoleInstances(int role) Count the number of active role instances on this node
int	getLiveRoleInstances(int role) Count the number of live role instances on this node
String	getNodeLabels()
NodeEntry	getOrCreate(org.apache.hadoop.yarn.api.records.Container container) Get the node entry matching a container on this node
NodeEntry	getOrCreate(int role) Get the entry for a role -if present
int	hashCode()
boolean	isConsideredUnreliable(int role, int threshold) Query for a node being considered unreliable
boolean	isOnline() Is the node considered online
boolean	purgeUnusedEntries(long absoluteTime) run through each entry; gc'ing & removing old ones that don't have a recent failure count (we care about those)
NodeEntry	remove(int role) Get the entry for a role -and remove it if present
void	resetFailedRecently() run through each entry resetting the failure count
NodeInformation	serialize(Map<Integer,String> naming) Produced a serialized form which can be served up as JSON
void	set(int role, NodeEntry nodeEntry)
String	toFullString() Full dump of entry including children
String	toString()
boolean	updateNode(org.apache.hadoop.yarn.api.records.NodeReport report) Update the node status.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

hostname

public final String hostname

Constructor Detail

NodeInstance

public NodeInstance(String hostname,
            int roles)

Create an instance and the (empty) array of nodes

Parameters:

roles - role count -the no. of roles

Method Detail

updateNode

public boolean updateNode(org.apache.hadoop.yarn.api.records.NodeReport report)

Update the node status. The return code is true if the node state changed enough to trigger a re-evaluation of pending requests. That is, either a node became available when it was previously not, or the label changed on an available node. Transitions of a node from live to dead aren't treated as significant, nor label changes on a dead node.

Parameters:

report - latest node report

Returns:

true if the node state changed enough for a request evaluation.

getNodeLabels

public String getNodeLabels()

get

public NodeEntry get(int role)

Get the entry for a role -if present

Parameters:

role - role index

Returns:

the entry null if the role is out of range

getOrCreate

public NodeEntry getOrCreate(int role)

Get the entry for a role -if present

Parameters:

role - role index

Returns:

the entry

Throws:

ArrayIndexOutOfBoundsException - if the role is out of range

getOrCreate

public NodeEntry getOrCreate(org.apache.hadoop.yarn.api.records.Container container)

Get the node entry matching a container on this node

Parameters:

container - container

Returns:

matching node instance for the role

getActiveRoleInstances

public int getActiveRoleInstances(int role)

Count the number of active role instances on this node

Parameters:

role - role index

Returns:

0 if there are none, otherwise the #of nodes that are running and not being released already.

getLiveRoleInstances

public int getLiveRoleInstances(int role)

Count the number of live role instances on this node

Parameters:

role - role index

Returns:

0 if there are none, otherwise the #of nodes that are running

isOnline

public boolean isOnline()

Is the node considered online

Returns:

the node

isConsideredUnreliable

public boolean isConsideredUnreliable(int role,
                             int threshold)

Query for a node being considered unreliable

Parameters:

role - role key

threshold - threshold above which a node is considered unreliable

Returns:

true if the node is considered unreliable

remove

public NodeEntry remove(int role)

Get the entry for a role -and remove it if present

Parameters:

role - the role index

Returns:

the entry that WAS there

set

public void set(int role,
       NodeEntry nodeEntry)

purgeUnusedEntries

public boolean purgeUnusedEntries(long absoluteTime)

run through each entry; gc'ing & removing old ones that don't have a recent failure count (we care about those)

Parameters:

absoluteTime - age in millis

Returns:

true if there are still entries left

resetFailedRecently

public void resetFailedRecently()

run through each entry resetting the failure count

toString

public String toString()

Overrides:

toString in class Object

toFullString

public String toFullString()

Full dump of entry including children

Returns:

a multi-line description fo the node

equals

public boolean equals(Object o)

Equality test is purely on the hostname of the node address

Overrides:

equals in class Object

Parameters:

o - other

Returns:

true if the hostnames are equal

hashCode

public int hashCode()

Overrides:

hashCode in class Object

exceedsFailureThreshold

public boolean exceedsFailureThreshold(RoleStatus role)

Predicate to query if the number of recent failures of a role on this node exceeds that role's failure threshold. If there is no record of a deployment of that role on this node, the failure count is taken as "0".

Parameters:

role - role to look up

Returns:

true if the failure rate is above the threshold.

serialize

public NodeInformation serialize(Map<Integer,String> naming)

Produced a serialized form which can be served up as JSON

Parameters:

naming - map of priority -> value for naming entries

Returns:

a summary of the current role status.

canHost

public boolean canHost(int role,
              String label)

Is this node instance a suitable candidate for the specific role?

Parameters:

role - role ID

label - label which must match, or "" for no label checks

Returns:

true if the node has space for this role, is running and the labels match.