hash_mod #
Description #
The hash_mod filter is used to obtain a unique partition number using the hash modulo of the request’s context. It is generally used for subsequent request forwarding.
Configuration Example #
A simple example is as follows:
flow:
- name: default_flow
filter:
- hash_mod: # Hash requests to different queues
source: "$[[_ctx.remote_ip]]_$[[_ctx.request.username]]_$[[_ctx.request.path]]"
target_context_name: "partition_id"
mod: 10 # Hash to 10 partitions
add_to_header: true
- set_context:
context:
_ctx.request.header.X-Replicated-ID: $[[_util.increment_id.request_number_id]]_$[[_util.generate_uuid]]
_ctx.request.header.X-Replicated-Timestamp: $[[_sys.unix_timestamp_of_now]]
_ctx.request.header.X-Replicated: "true"
Parameter Description #
| Name | Type | Description |
|---|---|---|
| source | string | Input for the hash, supports variable parameters |
| target_context_name | string | The primary key name to store the partition number in the context |
| mod | int | Maximum number of partitions |
| add_to_request_header | bool | Whether to add to the request header, default is true, creating X-Partition-ID and X-Partition-Size headers |
| add_to_response_header | bool | Whether to add to the response header, default is false |