Aggregation

Aggregation is performed by the Aggregator which collects partials results into a single unified response for a query. Similarly to the routing components, the Aggregator is deployed outside of an assembly so that it can aggregator across assemblies. It is primarily configured by setting environment variables on the service.

Environment Variables

Configuration can be supplied to the Aggregator using environment variables. Environment variables are configured differently depending on the method of deployment. In all cases, the variables are always string values.

DockerKubernetes

In Docker, environment variables are supplied using under an environment key for the target service as a list of key-value pairs.

services:
  agg:
    environment:
      - KXI_NAME=agg

In a Kubernetes deployment, environment variables are passed to compnents using a values file. For the Aggregator, these values are supplied under an aggregator key.

kdb Insights Enterprise

When running in an enterprise deployment, values are nested under either a service-gateway or qe-gateway key in the values file. See enterprise deployment configuration for more details.

service-gateway:
  aggregator:
    env:
      KXI_SG_TIMEOUT: "50000"

name	description
`KXI_NAME`	Process name.
`KXI_PORT`	Port.
`KXI_SG_RC_ADDR`	`host:port` of RC process to connect to.
`KXI_CUSTOM_FILE`	File containing custom code to load into Agg process.
`KXI_GC_FREQ`	Frequency in milliseconds to run garbage collect in a timer (default: `600000`, set to `0` to disable).
`KXI_SG_TIMEOUT`	Default request timeout in milliseconds (default: `30000`).
`KXI_SG_CONN_TIMEOUT`	Timeout on connection open.
`KXI_SG_REQ_DEL_FREQ`	Time in milliseconds to run the request table delete routine (default: `10000`).
`KXI_SAPI_HB_FREQ`	Time in milliseconds to run the heartbeat to connected processes (default: `30000`).
`KXI_SAPI_HB_TOL`	Number of heartbeat intervals a process can miss before being disconnected (default: `2`).
`KXI_ENABLE_FLUSH`	Set to `true` to enable async flush on messages from RC to DA/Agg and from Agg to GW (default `false`).
`KXI_DISC_MODE`	Discovery mode: `"kubernetes"` (currently only listed mode available, modes will be extended in future releases).Not required if using `KXI_SG_RC_ADDR`.
`KXI_RC_LABEL_SELECTOR`	Label selector to discover RCs via Kubernetes-based discovery (default: `app.kubernetes.io/name=resource-coordinator`).
`KXI_RC_CONTAINER_NAME`	RC container name for Kubernetes-based discovery (default: `resource-coordinator`).
`KXI_ORDINAL`	Override Aggregator's ordinal. See ordinals.