Batched commands

Jump to the Code block for a combined complete example.

Batched commands execute against multiple records issued as a single request. Batch reads support get, exists, getHeader, and operate requests. Batch writes, introduced in Aerospike 6.0.0, allow write requests against any keys, including updates, deletes, UDFs, and multi-operation operate commands.

Setup

The following examples will use the setup and record structure below to illustrate batch operations in an Aerospike database.

import aerospike
from aerospike_helpers import expressions as exp
from aerospike_helpers.operations import expression_operations, map_operations, operations
from aerospike_helpers.batch import records as br

# Define host configuration
config = {
    'hosts': [ ('127.0.0.1', 3000) ]
}
# Establishes a connection to the server
client = aerospike.client(config).connect()

The record structure:

Occurred: Integer
Reported: Integer
Posted: Integer
Report: Map
{
    shape: List,
    summary: String,
    city: String,
    state: String,
    duration: String
}
Location: GeoJSON

Policies

Policies are defined for the batch parent policy as well as batch read, batch write, batch delete, and batch UDF operations. Filter Expressions can be defined within each type of batch operation policy and the batch parent policy, along with other operation specific policies.

# An example that will always return true
expr = exp.GT(2, 1).compile()

# Create a new batch policy
batch_policy = {'expressions': expr}

# Create the batch write policy
batch_write_policy = {'expressions': expr}

Requests

Exists

The following example creates an array of ten keys and checks for their existence in the database.

# Create batch of keys
keys = []
for i in range(4995,5006):
    batch_key = ('sandbox', 'ufodata', i)
    keys.append(batch_key)

# Check if records exist
brs = client.batch_read(keys, bins=[])


# Access the records
for br in brs.batch_records:
    if br.result == 2: # "Record not found" error code
        print('Key: ', br.key, ' does not exist')

# Close the connection to the server
client.close()

Read records

The following example creates an array of ten keys and reads the records from the database; returning either the whole record or the specified report and location bins.

# Create batch of keys
keys = []
for i in range(1,11):
    batch_key = ('sandbox', 'ufodata', i)
    keys.append(batch_key)

# Read each whole record
brs = client.batch_read(keys);

# Or specify bins
# brs = client.batch_read(keys, bins=["report", "location"]);

# Access the records
for br in brs.batch_records:
    (key, meta, bins) = br.record
    # Do something
    print('Record: ', bins)

# Close the connection to the server
client.close()

Read commands

The following example creates an array of ten keys and accesses the city and state map keys to return their respective values from the report bin, for each record.

# Create batch of keys
keys = []
for i in range(1,11):
    batch_key = ('sandbox', 'ufodata', i)
    keys.append(batch_key)

# Create map key list
mapKeys = ['city', 'state']

# Create operations
ops = [
    map_operations.map_get_by_key_list('report', mapKeys, aerospike.MAP_RETURN_VALUE)
]


# Get 'city' and 'state' from report map for each record
brs = client.batch_operate(keys, ops)

# Access the records
for br in brs.batch_records:
    (key, meta, bins) = br.record
    # Do something
    print('Record: ', bins)

# Close the connection to the server
client.close()

Read/write operations

The following example creates an array of ten keys and

1. Defines an Operation Expression that compares the occurred bin value against the provided value, 20211231, and verifies the posted bin exists to determine the boolean value of the new recent key being added to the report map.
2. Returns the report bin.

# Create batch of keys
keys = []
for i in range(1,11):
    batch_key = ('sandbox', 'ufodata', i)
    keys.append(batch_key)

# Define Operation Expressions
expr = exp.MapPut(None, None, 'recent',
    exp.And(
        exp.GT(exp.IntBin('occurred'), 20211231),
        exp.BinExists('posted')
    ),
    exp.MapBin('report')).compile()

# Create operations
ops = [
    expression_operations.expression_write('report', expr, aerospike.EXP_WRITE_DEFAULT),
    operations.read('report')
]

# Execute the write operation and return the report bin
batchRecords = client.batch_operate(keys, ops)

# Access the records
for batchRecord in batchRecords.batch_records:
    (key, meta, bins) = batchRecord.record
    # Do something
    print('Record: ', bins)

# Close the connection to the server
client.close()

Delete operations

The following example deletes the records from the database.

# Create batch of keys
keys = []
for i in range(1,11):
    batch_key = ('sandbox', 'ufodata', i)
    keys.append(batch_key)

# Delete records passing null to use the default BatchDeletePolicy
batch_records = client.batch_remove(keys)

# Close the connection to the server
client.close()

Complex batched commands

The following example creates a list of four batch records that each use a differing set of operations.

The record with user defined key 4000

1. uses the ops1 array that combines the Operation Expression.
2. uses exp1 which compares the occurred bin value against the provided value, 20211231 and verifies the posted bin exists to determine the boolean value of the new recent key being added to the report map.
3. returns the report bin.

The record with user defined key 4001

1. uses the ops2 array which contains a read Operation Expression that gets the length of the shape list from the report map and returns the value in a synthetic bin named numShapes.

The record with user defined key 4002

1. uses the ops3 array which combines a write operation that updates the posted bin value, with a map operation that updates the city value in the report map.
2. returns both the posted and report bins.

The record with user defined key 4003 is deleted from the database.

# Define Operation Expressions
expr1 = exp.MapPut(None, None, 'recent',
    exp.And(
        exp.GT(exp.IntBin('occurred'), 20211231),
        exp.BinExists('posted')
    ),
    exp.MapBin('report')).compile()

expr2 = exp.ListSize(
    None,
    exp.MapGetByKey(None, aerospike.MAP_RETURN_VALUE, exp.ResultType.LIST, 'shape', exp.MapBin('report'))).compile()

# Define operations
ops1 = [
    expression_operations.expression_write('report', expr1, aerospike.EXP_WRITE_DEFAULT),
    operations.read('report')
]
ops2 = [
    expression_operations.expression_read('numShapes', expr2, aerospike.EXP_READ_DEFAULT)
]
ops3 = [
    operations.write('posted', 20201108),
    map_operations.map_put('report', 'city', 'Cedarville'),
    operations.read('posted'),
    operations.read('report')
]

# Create list of batch records to process
batch_records = br.BatchRecords(
    [
        br.Write(key=('sandbox', 'ufodata', 4000), ops=ops1),
        br.Read(key=('sandbox', 'ufodata', 4001), ops=ops2),
        br.Write(key=('sandbox', 'ufodata', 4002), ops=ops3),
        br.Remove(key=('sandbox', 'ufodata', 4003))
    ]
)

# Proccess the batch
client.batch_write(batch_records)

# Access the results
for batch_record in batch_records.batch_records:
    if not batch_record.record == None:
        (key, meta, bins) = batch_record.record
        # Do something
        print('Record: ', bins)

# Close the connection to the server
client.close()

Code block

Expand this section for a single code block to execute a batch read/write operation

import aerospike
from aerospike_helpers import expressions as exp
from aerospike_helpers.operations import expression_operations, map_operations, operations
from aerospike_helpers.batch import records as br

# Define host configuration
config = {
    'hosts': [ ('127.0.0.1', 3000) ]
}
# Establishes a connection to the server
client = aerospike.client(config).connect()

# An example that will always return true
expr = exp.GT(2, 1).compile()

# Create a new batch policy
batch_policy = {'expressions': expr}

# Create the batch write policy
batch_write_policy = {'expressions': expr}

# Create batch of keys
keys = []
for i in range(1,11):
    batch_key = ('sandbox', 'ufodata', i)
    keys.append(batch_key)

# Define Operation Expressions
expr = exp.MapPut(None, None, 'recent',
    exp.And(
        exp.GT(exp.IntBin('occurred'), 20211231),
        exp.BinExists('posted')
    ),
    exp.MapBin('report')).compile()

# Create operations
ops = [
    expression_operations.expression_write('report', expr, aerospike.EXP_WRITE_DEFAULT),
    operations.read('report')
]

# Execute the write operation and return the report bin
batchRecords = client.batch_operate(keys, ops)

# Access the records
for batchRecord in batchRecords.batch_records:
    (key, meta, bins) = batchRecord.record
    # Do something
    print('Record: ', bins)

# Close the connection to the server
client.close()