Resource Considerations
This document describes resource considerations and limitations to be taken into account when provisioning and operating a9s LogMe2 Service Instances.
The resource requirements of a Service Instance depend on the Template selected for its Service Plan. Each Template defines the topology (number of nodes) and the set of colocated processes. Templates that provide logging require a higher-memory VM type and more ephemeral disk than Templates without logging.
The Platform Operator must define matching vm_type and persistent_disk_type entries in the BOSH Cloud Config and
reference them from the Service Plan configuration. For guidance on Service Plans and Templates, see Service Plans
and Available Templates.
For guidance on Service Plans and Templates, see Service Plans and Available Templates.
Template Requirements
The resource requirements of a Service Instance depend on the Template selected for its Service Plan. The small,
medium, and large labels used for VM type and persistent disk type in the tables below refer to the example Cloud
Config entries defined in Update the Cloud Config.
The following table lists resource requirements per VM, as well as totals across all nodes of a Service Instance.
- Per VM
- Totals
| Template name | VM Role | Nodes | vCPUs | Logging | SSL | Min. RAM | Min. Persistent Disk | Min. Ephemeral Disk | Example VM Type | Example Persistent Disk Type |
|---|---|---|---|---|---|---|---|---|---|---|
logme2-single-ssl | OpenSearch | 1 | 4 | Yes | Yes | ≥ 8 GB | 20 GB | 5 GB | large | large |
| Fluentd | 1 | 2 | Yes | Yes | ≥ 4 GB | 0 GB | 5 GB | small | ||
| OpenSearch Dashboards | 1 | 2 | Yes | Yes | ≥ 2 GB | 0 GB | 5 GB | small | ||
logme2-cluster-ssl | OpenSearch | 3 | 4 | Yes | Yes | ≥ 8 GB | 20 GB | 5 GB | large | large |
| Fluentd | 1 | 2 | Yes | Yes | ≥ 4 GB | 0 GB | 5 GB | small | ||
| OpenSearch Dashboards | 1 | 2 | Yes | Yes | ≥ 2 GB | 0 GB | 5 GB | small |
| Template name | Nodes | vCPUs | Logging | SSL | Min. RAM | Min. Persistent Disk | Min. Ephemeral Disk |
|---|---|---|---|---|---|---|---|
logme2-single-ssl | 3 | 8 ‡ | Yes | Yes | ≥ 14 GB ‡ | 20 GB ‡ | 15 GB ‡ |
logme2-cluster-ssl | 5 | 16 ‡ | Yes | Yes | ≥ 30 GB ‡ | 60 GB ‡ | 25 GB ‡ |
| ‡ Each total is the sum of that column's value across all VMs of the Template (see the Per VM tab for the breakdown by role), not the value for a single VM. | |||||||
a9s LogMe2 runs more memory-intensive processes than most other Data Services: a JVM-based OpenSearch process with a substantial heap allocation, Fluentd for log ingestion, and OpenSearch Dashboards. A VM type with at least 8 GB of RAM is required for any a9s LogMe2 Template.
The recommended minimum disk type is a safe minimum; production deployments must plan capacity based on expected log volume and desired retention period.
Dependency on Trusted Certificates
In order to use the TLS syslog drain functionality and for the OpenSearch Dashboards to be reachable, either a CA or a wildcard certificate must be configured.
These certificates must also be trusted by Cloud Foundry.
This requirement also applies to user-provided certificates: the Certificate Authority (CA) used to sign them must be trusted by Cloud Foundry.
Fluentd
Buffers
Fluentd uses file buffers to mitigate the risk of data loss in the event of a system failure. File buffers provide durability guarantees that memory buffers cannot.
Plugins
This limitation applies to both OpenSearch and OpenSearch Dashboards plugins.
a9s LogMe2 restricts the set of enabled plugins to ensure integrity, stability, and usability of the service. This set of plugins is static and cannot be extended or modified by the Platform Operator.
The enabled OpenSearch plugins are:
opensearch-alertingopensearch-index-managementopensearch-job-scheduleropensearch-notificationsopensearch-notifications-coreopensearch-securityrepository-azurerepository-s3
The enabled OpenSearch Dashboards plugins are:
alertingDashboardsnotificationsDashboardssecurityDashboards