public sealed class ScanPolicy : Policy| ScanPolicy |
Default constructor. Disable totalTimeout and set maxRetries.
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. |
| ScanPolicy(ScanPolicy) | Copy scan policy from another scan policy. |
| SetTimeout |
Create a single timeout by setting socketTimeout and totalTimeout
to the same value.
(Inherited from Policy) |
| SetTimeouts |
Set socketTimeout and totalTimeout. If totalTimeout defined and
socketTimeout greater than totalTimeout, set socketTimeout to
totalTimeout.
(Inherited from Policy) |
| compress |
Use zlib compression on command buffers sent to the server and responses received
from the server when the buffer size is greater than 128 bytes.
This option will increase cpu and memory usage (for extra compressed buffers), but decrease the size of data sent over the network. Default: false (Inherited from Policy) |
| concurrentNodes |
Should scan requests be issued in parallel.
Default: true |
| failOnFilteredOut |
Throw exception if filterExp is defined and that filter evaluates
to false (transaction ignored). The AerospikeException
will contain result code .
This field is not applicable to batch, scan or query commands. Default: false (Inherited from Policy) |
| filterExp |
Optional expression filter. If filterExp exists and evaluates to false, the
transaction is ignored.
Default: null (Inherited from Policy) |
| includeBinData |
Should bin data be retrieved. If false, only record digests (and user keys
if stored on the server) are retrieved.
Default: true |
| 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) |
| 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.
Default: 0 (do not limit record count) |
| maxRetries |
Maximum number of retries before aborting the current transaction.
The initial attempt is not counted as a retry.
If maxRetries is exceeded, the transaction will abort with AerospikeExceptionTimeout. WARNING: Database writes that are not idempotent (such as Add()) should not be retried because the write operation may be performed multiple times if the client timed out previous transaction attempts. It's important to use a distinct WritePolicy for non-idempotent writes which sets maxRetries = 0; Default for write: 0 (no retries) Default for read: 2 (initial attempt + 2 retries = 3 attempts) Default for scan/query: 5 (6 attempts. See ScanPolicy comments.) (Inherited from Policy) |
| readModeAP |
Read policy for AP (availability) namespaces.
Default: ONE (Inherited from Policy) |
| readModeSC |
Read policy for SC (strong consistency) namespaces.
Default: SESSION (Inherited from Policy) |
| recordParser |
Alternate record parser.
Default: Use standard record parser. (Inherited from Policy) |
| recordQueueSize |
Number of records to place in queue before blocking.
Records received from multiple server nodes will be placed in a queue.
A separate thread consumes these records in parallel.
If the queue is full, the producer threads will block until records are consumed.
Default: 5000 |
| recordsPerSecond |
Limit returned records per second (rps) rate for each server.
Do not apply rps limit if recordsPerSecond is zero.
Default: 0 |
| replica |
Replica algorithm used to determine the target node for a partition derived from a key
or requested in a scan/query.
Default: SEQUENCE (Inherited from Policy) |
| sendKey |
Send user defined key in addition to hash digest on both reads and writes.
If the key is sent on a write, the key will be stored with the record on
the server.
Default: false (do not send the user defined key) (Inherited from Policy) |
| sleepBetweenRetries |
Milliseconds to sleep between retries. Enter zero to skip sleep.
This field is ignored when maxRetries is zero.
This field is also ignored in async mode.
The sleep only occurs on connection errors and server timeouts which suggest a node is down and the cluster is reforming. The sleep does not occur when the client's socketTimeout expires. Reads do not have to sleep when a node goes down because the cluster does not shut out reads during cluster reformation. The default for reads is zero. The default for writes is also zero because writes are not retried by default. Writes need to wait for the cluster to reform when a node goes down. Immediate write retries on node failure have been shown to consistently result in errors. If maxRetries is greater than zero on a write, then sleepBetweenRetries should be set high enough to allow the cluster to reform (>= 3000ms). Default: 0 (do not sleep between retries) (Inherited from Policy) |
| socketTimeout |
Socket idle timeout in milliseconds when processing a database command.
If socketTimeout is zero and totalTimeout is non-zero, then socketTimeout will be set to totalTimeout. If both socketTimeout and totalTimeout are non-zero and socketTimeout > totalTimeout, then socketTimeout will be set to totalTimeout. If both socketTimeout and totalTimeout are zero, then there will be no socket idle limit. If socketTimeout is not zero and the socket has been idle for at least socketTimeout, both maxRetries and totalTimeout are checked. If maxRetries and totalTimeout are not exceeded, the transaction is retried. For synchronous methods, socketTimeout is the socket SendTimeout and ReceiveTimeout. For asynchronous methods, the socketTimeout is implemented using the AsyncTimeoutQueue and socketTimeout is only used if totalTimeout is not defined. Default: 30000ms (Inherited from Policy) |
| totalTimeout |
Total transaction timeout in milliseconds.
The totalTimeout is tracked on the client and sent to the server along with the transaction in the wire protocol. The client will most likely timeout first, but the server also has the capability to timeout the transaction. If totalTimeout is not zero and totalTimeout is reached before the transaction completes, the transaction will abort with AerospikeExceptionTimeout. If totalTimeout is zero, there will be no total time limit. Default for scan/query: 0 (no time limit) Default for all other commands: 1000ms (Inherited from Policy) |