Scan

const Aerospike = require('aerospike')

// INSERT HOSTNAME AND PORT NUMBER OF AEROSPIKE SERVER NODE HERE!
var config = {
  hosts: '192.168.33.10:3000',
  // Timeouts disabled, latency dependent on server location. Configure as needed.
  policies: {
    scan : new Aerospike.ScanPolicy({socketTimeout : 0, totalTimeout : 0}),
   }
}

Aerospike.connect(config, (error, client) => {
  if (error) throw error

  const scan = client.scan('test', 'demo')
  let recordsSeen = 0
  const stream = scan.foreach()
  stream.on('error', (error) => { throw error })
  stream.on('end', () => client.close())
  stream.on('data', (record) => {
    console.log(record)
    recordsSeen++
    if (recordsSeen > 100) stream.abort() // We've seen enough!
  })
})

Members

concurrent :boolean

Description:

• If set to true, all cluster nodes will be scanned in parallel.

Source:

• scan.js, line 167

Type:

• boolean

nobins :boolean

Description:

• If set to true, the scan will return only meta data, and exclude bins.

Source:

• scan.js, line 160

Type:

• boolean

ns :string

Description:

• Namespace to scan.

Source:

• scan.js, line 136

Type:

• string

paginate :boolean

Description:

• If set to true, paginated queries are enabled. In order to receive paginated results, the ScanPolicy#maxRecords property must assign a nonzero integer value.

Source:

• scan.js, line 181

Type:

• boolean

Examples

Asynchronous pagination over a set of thirty records with Scan#foreach.

const Aerospike = require('./lib/aerospike');
// Define host configuration
let config = {
  hosts: '34.213.88.142:3000',
  policies: {
    batchWrite : new Aerospike.BatchWritePolicy({socketTimeout : 0, totalTimeout : 0}),
  }
};

var batchRecords = []
for(let i = 0; i < 30; i++){
  batchRecords.push({
    type: Aerospike.batchType.BATCH_WRITE,
    key: new Aerospike.Key('test', 'demo', 'key' + i),
    ops:[Aerospike.operations.write('exampleBin', i)]
  })
}

;(async function() {
  try {
    client = await Aerospike.connect(config)
    await client.truncate('test', 'demo', 0)
    await client.batchWrite(batchRecords, {socketTimeout : 0, totalTimeout : 0})

    const scan = client.scan('test', 'demo', {paginate: true})
    do {
      const stream = scan.foreach({maxRecords: 11})
      stream.on('error', (error) => { throw error })
      stream.on('data', (record) => {
        console.log(record.bins)
      })
      await new Promise(resolve => {
        stream.on('end', (scanState) => {
          scan.nextPage(scanState)
          console.log(scan.scanState)
          resolve()
        })
      })
    } while (scan.hasNextPage())

  } catch (error) {
    console.error('An error occurred at some point.', error)
    process.exit(1)
  } finally {
    if (client) client.close()
  }
})()

Asynchronous pagination over a set of thirty records with Scan#foreach.

const Aerospike = require('./lib/aerospike');
// Define host configuration
let config = {
  hosts: '34.213.88.142:3000',
  policies: {
    batchWrite : new Aerospike.BatchWritePolicy({socketTimeout : 0, totalTimeout : 0}),
  }
};

var batchRecords = []
for(let i = 0; i < 30; i++){
  batchRecords.push({
    type: Aerospike.batchType.BATCH_WRITE,
    key: new Aerospike.Key('test', 'demo', 'key' + i),
    ops:[Aerospike.operations.write('exampleBin', i)]
  })
}

;(async function() {
  try {
    client = await Aerospike.connect(config)
    await client.truncate('test', 'demo', 0)
    await client.batchWrite(batchRecords, {socketTimeout : 0, totalTimeout : 0})

    const scan = client.scan('test', 'demo', {paginate: true})
    let allResults = []
    let results = await scan.results({maxRecords: 11})
    allResults = [...allResults, ...results]


    results = await scan.results({maxRecords: 11})
    allResults = [...allResults, ...results]

    results = await scan.results({maxRecords: 11})
    allResults = [...allResults, ...results]

    console.log("Records returned in total: " + allResults.length)  // Should be 30 records

  } catch (error) {
    console.error('An error occurred at some point.', error)
    process.exit(1)
  } finally {
    if (client) client.close()
  }
})()

scanState :number

Description:

• If set to a valid serialized scan, calling scan#foreach will allow the next page of records to be queried while preserving the progress of the previous scan. If set to null, calling scan#foreach will begin a new scan.

Source:

• scan.js, line 288

Type:

• number

selected :Array.<string>

Description:

• List of bin names to be selected by the scan. If a scan specifies bins to be selected, then only those bins will be returned. If no bins are selected, then all bins will be returned (unless Scan#nobins is set to true).

Source:

• scan.js, line 148

See:

• Use Scan#select to specify the bins to select.

Type:

• Array.<string>

set :string

Description:

• Name of the set to scan.

Source:

• scan.js, line 142

Type:

• string

ttl :number

Description:

• The time-to-live (expiration) of the record in seconds. There are also special values that can be set in the record TTL:

  0 (defined Aerospike.ttl.NAMESPACE_DEFAULT), which means that the record will adopt the default TTL value from the namespace.

  -1 (defined Aerospike.ttl.NEVER_EXIRE), which means that the record will get an internal "void_time" of zero, and thus will never expire.

  -2 (defined Aerospike.ttl.DONT_UPDATE), which means that the record ttl will not change when the record is updated.

  Note that the TTL value will be employed ONLY on background scan writes.

Source:

• scan.js, line 295

Type:

• number

Methods

background(udfModule, udfFunction, udfArgsopt, policyopt, scanIDopt, callbackopt) → (nullable) {Promise}

Perform a read-write background scan and apply a Lua user-defined function (UDF) to each record.

Description:

• When a background scan is initiated, the client will not wait for results from the database. Instead a Job instance will be returned, which can be used to query the scan status on the database.

Source:

• scan.js, line 379

Parameters:

Returns:

Type

Promise

foreach(policyopt, dataCbopt, errorCbopt, endCbopt) → {RecordStream}

Performs a read-only scan on each node in the cluster. As the scan iterates through each partition, it returns the current version of each record to the client.

Source:

• scan.js, line 473

Parameters:

Returns:

Type

RecordStream

hasNextPage() → {boolean}

Checks compiliation status of a paginated scan.

Description:

• If false is returned, there are no more records left in the scan, and the scan is complete. If true is returned, calling Scan#foreach will continue from the state specified by Scan#scanState.

Source:

• scan.js, line 327

Returns:

Type

boolean

nextPage(…state)

Sets scan#scanState to the value specified by the state argument.

Description:

• setter function for the Scan#scanState member variable.

Source:

• scan.js, line 314

Parameters:

operate(operations, policyopt, scanIDopt, callbackopt) → (nullable) {Promise}

Applies write operations to all matching records.

Description:

• Performs a background scan and applies one or more write operations to all records. Neither the records nor the results of the operations are returned to the client. Instead a Job instance will be returned, which can be used to query the scan status.

  This method requires server >= 3.7.0.

Source:

• scan.js, line 422

Since:

• v3.14.0

Example

Increment count bin on all records in set using a background scan

const Aerospike = require('aerospike')

// INSERT HOSTNAME AND PORT NUMBER OF AEROSPIKE SERVER NODE HERE!
var config = {
  hosts: '192.168.33.10:3000',
  // Timeouts disabled, latency dependent on server location. Configure as needed.
  policies: {
    scan : new Aerospike.ScanPolicy({socketTimeout : 0, totalTimeout : 0})
   }
}

Aerospike.connect(config).then(async (client) => {
  const scan = client.scan('namespace', 'set')
  const ops = [Aerospike.operations.incr('count', 1)]
  const job = await scan.operate(ops)
  await job.waitUntilDone()
  client.close()
})

Parameters:

Returns:

Type

Promise

partitions(begin, count, digest)

Specify the begin and count of the partitions to be scanned by the scan foreach op.

Description:

• If a scan specifies partitions begin and count, then only those partitons will be scanned and returned. If no partitions are specified, then all partitions will be scanned and returned.

Source:

• scan.js, line 359

Parameters:

results(policyopt) → {Promise.<Array.<RecordObject>>}

Executes the Scan and collects the results into an array. On paginated queries, preparing the next page is also handled automatically.

Description:

• This method returns a Promise that contains the scan results as an array of records, when fulfilled. It should only be used if the scan is expected to return only few records; otherwise it is recommended to use Scan#foreach, which returns the results as a RecordStream instead.

  If pagination is enabled, the data emitted from the RecordStream#event:error event will automatically be assigned to Scan#scanState, allowing the next page of records to be queried if Scan#foreach or Scan#results is called.

Source:

• scan.js, line 510

Parameters:

Returns:

Type

Promise.<Array.<RecordObject>>

select(…bins)

Specify the names of bins to be selected by the scan.

Description:

• If a scan specifies bins to be selected, then only those bins will be returned. If no bins are selected, then all bins will be returned. (Unless Scan#nobins is set to true.)

Source:

• scan.js, line 340

Parameters: