com.aerospike.client.policy

Class ScanPolicy

java.lang.Object

com.aerospike.client.policy.Policy

com.aerospike.client.policy.ScanPolicy

public final class ScanPolicy
extends Policy

Container object for optional parameters used in scan operations.

Field Summary

Fields

Modifier and Type	Field and Description
boolean	concurrentNodes Should scan requests be issued in parallel.
boolean	failOnClusterChange Terminate scan if cluster in migration state.
boolean	includeBinData Should bin data be retrieved.
int	maxConcurrentNodes Maximum number of concurrent requests to server nodes at any point in time.
long	maxRecords Approximate number of records to return to client.
int	recordsPerSecond Limit returned records per second (rps) rate for each server.
int	scanPercent Percent of data to scan.

Fields inherited from class com.aerospike.client.policy.Policy

compress, failOnFilteredOut, maxRetries, predExp, priority, readModeAP, readModeSC, replica, sendKey, sleepBetweenRetries, socketTimeout, timeoutDelay, totalTimeout

Constructor Summary

Constructors

Constructor and Description
ScanPolicy() Default constructor.
ScanPolicy(Policy other) Copy scan policy from another policy.
ScanPolicy(ScanPolicy other) Copy scan policy from another scan policy.

Method Summary

Modifier and Type	Method and Description
void	validate() Verify policies fields are within range.

Methods inherited from class com.aerospike.client.policy.Policy

setPredExp, setTimeout, setTimeouts

Methods inherited from class java.lang.Object

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

Field Detail

maxRecords

public long maxRecords

Approximate number of records to return to client. This number is divided by the number of nodes involved in the scan. The actual number of records returned may be less than maxRecords if node record counts are small and unbalanced across nodes.

This field is supported on server versions >= 4.9.

Default: 0 (do not limit record count)

scanPercent

public int scanPercent

Percent of data to scan. Valid integer range is 1 to 100.

This field is supported on server versions < 4.9. Server versions >= 4.9 might allow scanPercent, but not in conjunction with maxRecords. scanPercent is eventually slated for removal.

Default: 100

recordsPerSecond

public int recordsPerSecond

Limit returned records per second (rps) rate for each server. Do not apply rps limit if recordsPerSecond is zero.

Default: 0

maxConcurrentNodes

public int maxConcurrentNodes

Maximum number of concurrent requests to server nodes at any point in time. If there are 16 nodes in the cluster and maxConcurrentNodes is 8, then scan requests will be made to 8 nodes in parallel. When a scan completes, a new scan request will be issued until all 16 nodes have been scanned.

This field is only relevant when concurrentNodes is true.

Default: 0 (issue requests to all server nodes in parallel)

concurrentNodes

public boolean concurrentNodes

Should scan requests be issued in parallel.

Default: true

includeBinData

public boolean includeBinData

Should bin data be retrieved. If false, only record digests (and user keys if stored on the server) are retrieved.

Default: true

failOnClusterChange

public boolean failOnClusterChange

Terminate scan if cluster in migration state. Only used for server versions < 4.9.

Default: false

Constructor Detail

ScanPolicy

public ScanPolicy(ScanPolicy other)

Copy scan policy from another scan policy.

ScanPolicy

public ScanPolicy(Policy other)

Copy scan policy from another policy.

ScanPolicy

public ScanPolicy()

Default constructor.

Set maxRetries for scans on server versions >= 4.9. All other scans are not retried.

The latest servers support retries on individual data partitions. This feature is useful when a cluster is migrating and partition(s) are missed or incomplete on the first scan attempt.

If the first scan attempt misses 2 of 4096 partitions, then only those 2 partitions are retried in the next scan attempt from the last key digest received for each respective partition. A higher default maxRetries is used because it's wasteful to invalidate all scan results because a single partition was missed.

Method Detail

validate

public void validate()

Verify policies fields are within range.