org.apache.cassandra.service

Class FileSystemOwnershipCheck

java.lang.Object

org.apache.cassandra.service.FileSystemOwnershipCheck

All Implemented Interfaces:

StartupCheck

public class FileSystemOwnershipCheck
extends java.lang.Object
implements StartupCheck

Ownership markers on disk are compatible with the java property file format. (https://docs.oracle.com/javase/8/docs/api/java/util/Properties.html#load-java.io.Reader-) This simple formatting is intended to enable them to be created either manually or by automated tooling using minimal standard tools (editor/shell builtins/etc). The only mandatory property is version, which must be parseable as an int and upon which the futher set of required properties will depend. In version 1, two further property values are required: - volume_count to be parsed as an int representing the number of mounted volumes where a marker file is expected. - ownership_token must contain a non-empty token string that can be compared to one derived from system properties. For version 1, this is simply the cluster name. For this check to succeed as of version 1 then: - There must be a single properties file found in the fs tree for each target directory. - Every file found must contain the mandatory version property with the literal value '1'. - The value of the ownership_token property in each file must match the cluster name - The value of the volume_count property must be an int which must matches the number of distinct marker files found when traversing the filesystem. In overridden implementations, you will need to override constructTokenFromProperties(Map) and add the related *_PROPERTY values you will want the system to check on startup to confirm ownership.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_FS_OWNERSHIP_FILENAME
static java.lang.String	FILE_SYSTEM_CHECK_OWNERSHIP_TOKEN

Method Summary

Modifier and Type	Method and Description
protected java.lang.String	constructTokenFromProperties(java.util.Map<java.lang.String,java.lang.Object> config) In version 1, we check and return the ownership token.
void	execute(StartupChecksOptions options) Run some test to determine whether the system is safe to be started In the case where a test determines it is not safe to proceed, the test should log a message regarding the reason for the failure and ideally the steps required to remedy the problem.
java.lang.String	getFsOwnershipFilename(java.util.Map<java.lang.String,java.lang.Object> config)
java.lang.String	getOwnershipToken(java.util.Map<java.lang.String,java.lang.Object> config)
StartupChecks.StartupCheckType	getStartupCheckType()
boolean	isEnabled(StartupChecksOptions options)

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.service.StartupCheck

postAction

Field Detail

FILE_SYSTEM_CHECK_OWNERSHIP_TOKEN

public static final java.lang.String FILE_SYSTEM_CHECK_OWNERSHIP_TOKEN

See Also:

Constant Field Values

DEFAULT_FS_OWNERSHIP_FILENAME

public static final java.lang.String DEFAULT_FS_OWNERSHIP_FILENAME

See Also:

Constant Field Values

Method Detail

getStartupCheckType

public StartupChecks.StartupCheckType getStartupCheckType()

Specified by:

getStartupCheckType in interface StartupCheck

Returns:

type of this startup check for configuration retrieval

execute

public void execute(StartupChecksOptions options)
             throws StartupException

Description copied from interface: StartupCheck

Run some test to determine whether the system is safe to be started In the case where a test determines it is not safe to proceed, the test should log a message regarding the reason for the failure and ideally the steps required to remedy the problem.

Specified by:

execute in interface StartupCheck

Parameters:

options - all options from descriptor

Throws:

StartupException - if the test determines that the environement or system is not in a safe state to startup

constructTokenFromProperties

protected java.lang.String constructTokenFromProperties(java.util.Map<java.lang.String,java.lang.Object> config)
                                                 throws StartupException

In version 1, we check and return the ownership token. Extend this for custom ownership hierarchies.

Throws:

StartupException

isEnabled

public boolean isEnabled(StartupChecksOptions options)

getFsOwnershipFilename

public java.lang.String getFsOwnershipFilename(java.util.Map<java.lang.String,java.lang.Object> config)

getOwnershipToken

public java.lang.String getOwnershipToken(java.util.Map<java.lang.String,java.lang.Object> config)