Size the cluster

This section is a guide to size base resource needs of a Loki cluster.

Based on the expected ingestion volume, Loki clusters can be categorised into three tiers. Recommendations below are based on p90 resource utilisations of the relevant components. Each tab represents a different tier. Please use this document as a rough guide to specify CPU and Memory requests in your deployment. This is only documented for microservices/distributed mode at this time.

Query resource needs can greatly vary with usage patterns and correct configurations. General notes on Query Performance:

The rule of thumb is to run as small and as many queriers as possible. Unoptimised queries can easily require 10x of the suggested querier resources below in all tiers. Running horizontal autoscaling will be most cost effective solution to meet the demand.
Use this blog post to adopt best practices for optimised query performance.
Parallel-querier and related components can be sized the same along with queriers to start, depending on how much Loki rules are used.
Large Loki clusters benefit from a disk based caching solution, memcached-extstore. Please see the detailed blog post and read more about memcached/nvm-caching here.
If you’re running a cluster that handles less than 30TB/day (~1PB/month) ingestion, we do not recommend configuring memcached-extstore. The additional operational complexity does not justify the savings.

Component	CPU Request	Memory Request (Gi)	Base Replicas	Total CPU Req	Total Mem Req (Gi)
Ingester	2	4	6	12	36
Distributor	2	0.5	4	8	2
Index gateway	0.5	2	4	2	8
Querier	1	1	10	10	10
Query-frontend	1	2	2	2	4
Query-scheduler	1	0.5	2	2	1
Compactor	2	10	1 (Singleton)	2	10

Component	CPU Request	Memory Request (Gi)	Base Replicas	Total CPU Req	Total Mem Req (Gi)
Ingester	2	6	90	180	540
Distributor	2	1	40	80	40
Index gateway	0.5	4	10	5	40
Querier	1.5	2	100	150	200
Query-frontend	1	2	8	8	16
Query-scheduler	1	0.5	2	2	1
Compactor	6	20	1 (Singleton)	6	20

Component	CPU Request	Memory Request (Gi)	Base Replicas	Total CPU Req	Total Mem Req (Gi)
Ingester	4	8	150	600	1200
Distributor	2	1	100	200	100
Index gateway	1	4	20	20	80
Querier	1.5	3	250	375	750
Query-frontend	1	4	16	16	64
Query-scheduler	2	0.5	2	4	1
Compactor	6	40	1 (Singleton)	6	40

Instance Types

These are the node types we suggest from various cloud providers. Please see the relevant specifications in the provider’s documentation.

For AWS any General Purpose machine available in your region that belongs to M6 instance family and above for Intel chips and T2 machine family and above for ARM chips.
For GCP any General Purpose machine available in your region that belongs to to E2 instance family and above.
For memcached-extstore nodes we suggest storage optimised instances that can has NVMe storage so that the additional disk space is utilized.