diff --git a/README.md b/README.md index f33d534d6..a2817f104 100644 --- a/README.md +++ b/README.md @@ -184,6 +184,33 @@ Cluster should remain in working state if at least a single node of each type re the update process. See [cluster availability](#cluster-availability) section for details. +### Capacity planning + +Each instance type - `vminsert`, `vmselect` and `vmstorage` - can run on the most suitable hardware. + +#### vminsert + +* The recommended total number of vCPU cores for all the `vminsert` instances can be calculated from the ingestion rate: `vCPUs = ingestion_rate / 150K`. +* The recommended number of vCPU cores per each `vminsert` instance should equal to the number of `vmstorage` instances in the cluster. +* The amount of RAM per each `vminsert` instance should be 1GB or more. RAM is used as a buffer for spikes in ingestion rate. +* Sometimes `-rpc.disableCompression` command-line flag on `vminsert` instances could increase ingestion capacity at the cost + of higher network bandwidth usage between `vminsert` and `vmstorage`. + +#### vmstorage + +* The recommended total number of vCPU cores for all the `vmstorage` instances can be calculated from the ingestion rate: `vCPUs = ingestion_rate / 150K`. +* The recommended total amount of RAM for all the `vmstorage` instances can be calculated from the number of active time series: `RAM = active_time_series * 1KB`. + Time series is active if it received at least a single data point during the last hour or if it has been queried during the last hour. +* The recommended total amount of storage space for all the `vmstorage` instances can be calculated + from the ingestion rate and retention: `storage_space = ingestion_rate * retention_seconds`. + +#### vmselect + +The recommended hardware for `vmselect` instances highly depends on the type of queries. Lightweight queries over small number of time series usually require +small number of vCPU cores and small amount of RAM on `vmselect`, while heavy queries over big number of time series (>10K) usually require +bigger number of vCPU cores and bigger amounts of RAM. + + ### Helm Helm chart simplifies managing cluster version of VictoriaMetrics in Kubernetes.