Memcached

Learn more about the component and how to use it.

The Memcached component allows you to perform operations on Memcached servers.

Memcached is an open source distributed memory caching system that uses an in-memory key-value model for data storage. For more information, see the official website.

Parameters

Take a look at the configuration parameters of the component. Parameters supported by Double Braces expressions are marked with (DB).

Parameter

Description

Default value

Data yype

Account

Account to be used to authenticate on servers. Supported accounts: Basic.

N/A

String

Operation

Operation to be performed. The operations are: Get One, Get Many, Add, Set, Delete, Replace, Append, Prepend, Touch, Get And Touch, and CAS (Check And Set).

Get One

String

Addresses (DB)

Host and port (HOST:PORT) of the servers to connect to. Multiple addresses can be configured as HOST1:PORT1, HOSTn:PORTn.

N/A

String

Key (DB)

Key to be stored or retrieved.

N/A

String

Key Set (DB)

Key set to be retrieved. This option is only available when using operation Get Many and it expects an array of Strings containing the keys.

N/A

Array of Strings

Expiration

Time (in seconds) that the data must be kept in the database before expiring. If set with 0, the data will not expire.

N/A

Integer

Value (DB)

Value to be stored.

N/A

String

Connect Timeout

Maximum time (in milliseconds) to connect to Memcached servers.

30000

Integer

Operation Timeout

Maximum time (in milliseconds) to perform the Memcached operation.

30000

Integer

Advanced Settings

If the option is active, you can access the following configurations:

False

Boolean

- Raw Mode

When enabled, will consider Value as raw data (not JSON) and will store it as is. Retrieved content will also be displayed as a string with a raw result.

False

Boolean

- Is Binary Result

If enabled, will treat the result as binary content and will show output as a Base64 string.

False

Boolean

- Pool Size By Actual Consumers

If enabled, the number of pooled connections will be equivalent to the number of consumers configured during pipeline deployment. If disabled, then the pool size is given by the pipeline deployment size, irrespective of the number of consumers.

False

Boolean

Fail On Error

If the option is active, the execution of the pipeline with an error will be interrupted. Otherwise, the pipeline execution proceeds, but the result will show a false value for the “success” property.

False

Boolean

Important: when using multiple servers, the same Basic credential must be used through all servers.

Usage examples

Retrieval operations

Get One

Retrieves only 1 record from the server by its Key.

Account: <basic-account>
Addresses: localhost:11211
Operation: Get One
Key: id_A

Output:

{
    "total": 1,
    "data": [
        {
        	"key": "id_A",
        	"value": <value>
        }
    ]
}

Get Many

Retrieve any number of records from the server by a Key Set.

Account: <basic-account>
Address: localhost:11211
Operation: Get Many
Key Set:

[
	"id_A",
	"id_B",
	"id_C",
	"id_D"
]

Output:

{
    "total": 4,
    "data": [
        {
        	"key": "id_A",
        	"value": <value>
        },
        {
        	"key": "id_B",
        	"value": <value>
        },
        {
        	"key": "id_C",
        	"value": <value>
        },
        {
        	"key": "id_D",
        	"value": <value>
        }
    ]
}

Important: when retrieving data from a Memcached server, the component can only handle Java serializable objects and will always try to output them in JSON format or its string representation. If the retrieved value cannot be parsed into these formats, an Exception can be thrown.

Storage operations

Add

Stores a record on the server by its Key, Expiration and Value, only if it does not already exist.

Account: <basic-account>
Addresses: localhost:11211
Operation: Add
Key: id_A
Expiration: 3600
Value:

{
    "code": "A",
    "name": "John",
    "address": {
    	"street": "John's Street"
    },
    "number": [
    	"+5511999999999"
    ]
}

Output:

{
    "success": true,   //false, if the key already exists
    "command": "add"
}

Set

Stores a record on the server by its Key, Expiration and Value, overriding it if it already exists.

Account: <basic-account>
Addresses: localhost:11211
Operation: Set
Key: id_A
Expiration: 3600
Value:

{
    "code": "A",
    "name": "John",
    "address": {
    	"street": "John's Street"
    },
    "number": [
    	"+5511999999999"
    ]
}

Output:

{
    "success": true,
    "command": "set"
}

Replace

Replaces a record's Value by its Key, Expiration and the new Value, only if the record already exists.

Account: <basic-account>
Addresses: localhost:11211
Operation: Replace
Key: id_A
Expiration: 3600
Value:

{
    "code": "A",
    "name": "John",
    "address": {
    	"street": "John's Street"
    },
    "number": [
    	"+5511999999999"
    ]
}

Output:

{
    "success": true,   //false, if the key does not exist
    "command": "replace"
}

Append

Appends a value to a record's Value by its Key and the Value to be appended, only if the record already exists. Requires Raw Mode parameter to be enabled.

Account: <basic-account>
Addresses: localhost:11211
Operation: Append
Key: id_A
Expiration: 3600
Raw Mode: enabled
Value:

" - value to be appended"

Output:

{
    "success": true,   //false, if the key does not exist
    "command": "append"
}

Important: since the Append operation appends new data to existing data without retrieving it, it is not possible to simply append complex data structures such as JSON objects. Therefore, the existing data must also have been stored as raw data, and the Raw Mode parameter must be enabled for this operation.

Prepend

Prepends a value to a record's Value by its Key and the Value to be prepended, only if the record alright exists. Requires Raw Mode parameter to be enabled.

Account: <basic-account>
Addresses: localhost:11211
Operation: Prepend
Key: id_A
Expiration: 3600
Raw Mode: enabled
Value:

"value to be prepended - "

Output:

{
    "success": true,   //false, if the key does not exist
    "command": "prepend"
}

Important: since the Prepend operation prepends new data to existing data without retrieving it, it is not possible to simply prepend complex data structures such as JSON objects. Therefore, the existing data must also have been stored as raw data, and the Raw Mode parameter must be enabled for this operation.

CAS (Check And Set)

Update a record's Value by its Key, Expiration and the new Value, only if the record alright exists and if it wasn't changed during the record's retrieval. This operation is useful in environments with race conditions on updating cache data.

Account: <basic-account>
Addresses: localhost:11211
Operation: CAS (Check And Set)
Key: id_A
Expiration: 3600
Value:

{
    "code": "A",
    "name": "John",
    "address": {
    	"street": "John's Street"
    },
    "number": [
    	"+5511999999999"
    ]
}

Output:

{
    "success": true,   //false, if the key does not exist
    "command": "cas"
}

Delete operations

Delete

Delete a record from the server by its Key.

Account: <basic-account>
Addresses: localhost:11211
Operation: Delete
Key: id_A

Output:

{
    "success": true,    //false, if the key does not exist
    "command": "delete"
}

Touch operations

Touch

Updates a record's expiration by its Key and a new Expiration value.

Account: <basic-account>
Addresses: localhost:11211
Operation: Touch
Key: id_A
Expiration: 3600

Output:

{
    "success": true,    //false, if the key does not exist
    "command": "touch"
}

Get And Touch

Retrieves only 1 record from the server by its Key while updating its Expiration value.

Account: <basic-account>
Addresses: localhost:11211
Operation: Get And Touch
Key: id_A
Expiration: 3600

Output:

{
    "total": 1,
    "data": [
        {
        	"key": "id_A",
        	"value": <value>
        }
    ]
}

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Last updated 1 year ago