Package org.apache.cassandra.locator

Class Ec2Snitch

java.lang.Object

org.apache.cassandra.locator.AbstractEndpointSnitch

org.apache.cassandra.locator.AbstractNetworkTopologySnitch

org.apache.cassandra.locator.Ec2Snitch

All Implemented Interfaces:

IEndpointSnitch

Direct Known Subclasses:

Ec2MultiRegionSnitch

public class Ec2Snitch
extends AbstractNetworkTopologySnitch

A snitch that assumes an EC2 region is a DC and an EC2 availability_zone is a rack. This information is available in the config for the node. Since CASSANDRA-16555, it is possible to choose version of AWS IMDS. By default, since CASSANDRA-16555, IMDSv2 is used. The version of IMDS is driven by property Ec2MetadataServiceConnector.EC2_METADATA_TYPE_PROPERTY and can be of value either 'v1' or 'v2'. It is possible to specify custom URL of IMDS by Ec2MetadataServiceConnector.EC2_METADATA_URL_PROPERTY. A user is not meant to change this under normal circumstances, it is suitable for testing only. IMDSv2 is secured by a token which needs to be fetched from IDMSv2 first, and it has to be passed in a header for the actual queries to IDMSv2. Ec2Snitch is doing this automatically. The only configuration parameter exposed to a user is Ec2MetadataServiceConnector.V2Connector.AWS_EC2_METADATA_TOKEN_TTL_SECONDS_HEADER_PROPERTY which is by default set to Ec2MetadataServiceConnector.V2Connector.MAX_TOKEN_TIME_IN_SECONDS. TTL has to be an integer from the range [30, 21600].

Field Summary

Fields

Modifier and Type	Field	Description
protected final org.apache.cassandra.locator.AbstractCloudMetadataServiceConnector	connector
static final String	ZONE_NAME_QUERY

Constructor Summary

Constructors

Constructor	Description
Ec2Snitch()
Ec2Snitch(SnitchProperties props)

Method Summary

Modifier and Type	Method	Description
final String	getDatacenter(InetAddressAndPort endpoint)	Return the data center for which an endpoint resides in
final String	getLocalDatacenter()	returns a String representing the datacenter current endpoint belongs to
final String	getLocalRack()	returns a String representing the rack current endpoint belongs to
final String	getRack(InetAddressAndPort endpoint)	Return the rack for which an endpoint resides in
boolean	validate(Set<String> datacenters, Set<String> racks)	Determine if the datacenter or rack values in the current node's snitch conflict with those passed in parameters.

Methods inherited from class org.apache.cassandra.locator.AbstractNetworkTopologySnitch

compareEndpoints

Methods inherited from class org.apache.cassandra.locator.AbstractEndpointSnitch

gossiperStarting, isWorthMergingForRangeQuery, sortedByProximity

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.cassandra.locator.IEndpointSnitch

getDatacenter, getDatacenter

Field Details

ZONE_NAME_QUERY

public static final String ZONE_NAME_QUERY

See Also:

• Constant Field Values

connector

protected final org.apache.cassandra.locator.AbstractCloudMetadataServiceConnector connector

Constructor Details

Ec2Snitch

public Ec2Snitch()
          throws IOException,
ConfigurationException

Throws:

IOException

ConfigurationException

Ec2Snitch

public Ec2Snitch(SnitchProperties props)
          throws IOException,
ConfigurationException

Throws:

IOException

ConfigurationException

Method Details

validate

public boolean validate(Set<String> datacenters,
 Set<String> racks)

Description copied from interface: IEndpointSnitch

Determine if the datacenter or rack values in the current node's snitch conflict with those passed in parameters.

getLocalRack

public final String getLocalRack()

Description copied from interface: IEndpointSnitch

returns a String representing the rack current endpoint belongs to

getLocalDatacenter

public final String getLocalDatacenter()

Description copied from interface: IEndpointSnitch

returns a String representing the datacenter current endpoint belongs to

getRack

public final String getRack(InetAddressAndPort endpoint)

Description copied from class: AbstractNetworkTopologySnitch

Return the rack for which an endpoint resides in

Specified by:

getRack in interface IEndpointSnitch

Specified by:

getRack in class AbstractNetworkTopologySnitch

Parameters:

endpoint - a specified endpoint

Returns:

string of rack

getDatacenter

public final String getDatacenter(InetAddressAndPort endpoint)

Description copied from class: AbstractNetworkTopologySnitch

Return the data center for which an endpoint resides in

Specified by:

getDatacenter in interface IEndpointSnitch

Specified by:

getDatacenter in class AbstractNetworkTopologySnitch

Parameters:

endpoint - a specified endpoint

Returns:

string of data center