# Resilience — what the source states against what the business requires

> PROPOSAL — generated by StackToIT Assess. Architect review required before any decision.

Run `f6267c3f-2848-4aa5-89df-5fee8b15b3b9` · source digest `sha256:812c5ae3f6cc8530163abbf5b6fbe305ed3b363c4886ec6b87623db857ea0c70`

Do not call architecture resilient against an unknown requirement. No unit below is called resilient, and no resilience intent is chosen.

## The requirement

Requirement: `BUSINESS_REQUIREMENT_NOT_PROVIDED`. No RTO or RPO was stated (BUSINESS_REQUIREMENT_NOT_PROVIDED): no architecture is called resilient against it, and no value is assumed.

## State of the dimension

Resilience: EVIDENCE REQUIRED.

## Units

| Unit | Source type | Application | Intent | State |
|---|---|---|---|---|
| module.dependencies.module.catalog_opensearch.aws_opensearch_domain.this | aws_opensearch_domain |  | UNKNOWN | EVIDENCE_REQUIRED |
| module.dependencies.module.catalog_rds.aws_rds_cluster.this | aws_rds_cluster |  | UNKNOWN | EVIDENCE_REQUIRED |
| module.dependencies.module.checkout_elasticache_redis.aws_elasticache_replication_group.default | aws_elasticache_replication_group |  | UNKNOWN | EVIDENCE_REQUIRED |
| module.dependencies.module.dynamodb_carts.aws_dynamodb_table.this | aws_dynamodb_table |  | UNKNOWN | EVIDENCE_REQUIRED |
| module.dependencies.module.orders_rds.aws_rds_cluster.this | aws_rds_cluster |  | UNKNOWN | EVIDENCE_REQUIRED |
| module.retail_app_ecs.module.alb.aws_lb.this | aws_lb |  | UNKNOWN | EVIDENCE_REQUIRED |

## What the source states, unit by unit

### `module.dependencies.module.catalog_opensearch.aws_opensearch_domain.this`

Intent UNKNOWN: decision requires evidence. No applications file was given, so no RTO or RPO is stated. The availability-zone and metro placement of the target are NOT_ASSESSED: this build holds no evidence for them.

| Fact | As the source states it | What it is not |
|---|---|---|
| availability zone | not stated in the source | an absent zone is not read as a default zone |

### `module.dependencies.module.catalog_rds.aws_rds_cluster.this`

Intent UNKNOWN: decision requires evidence. No applications file was given, so no RTO or RPO is stated. The availability-zone and metro placement of the target are NOT_ASSESSED: this build holds no evidence for them.

| Fact | As the source states it | What it is not |
|---|---|---|
| availability zone | not stated in the source | an absent zone is not read as a default zone |
| contract item backup-retention | observed yes; disposition LEDGER | the state of the contract item, not a setting of the target |
| contract item readable-standbys | observed yes; disposition NOT_APPLICABLE | the state of the contract item, not a setting of the target |

### `module.dependencies.module.checkout_elasticache_redis.aws_elasticache_replication_group.default`

Intent UNKNOWN: decision requires evidence. No applications file was given, so no RTO or RPO is stated. The availability-zone and metro placement of the target are NOT_ASSESSED: this build holds no evidence for them.

| Fact | As the source states it | What it is not |
|---|---|---|
| multi-zone switch of the service | false | the switch as the source writes it |

### `module.dependencies.module.dynamodb_carts.aws_dynamodb_table.this`

Intent UNKNOWN: decision requires evidence. No applications file was given, so no RTO or RPO is stated. The availability-zone and metro placement of the target are NOT_ASSESSED: this build holds no evidence for them.

| Fact | As the source states it | What it is not |
|---|---|---|
| availability zone | NOT_ASSESSED: no placement adapter reads this source type in this build | not read, which is not the same as not stated |

### `module.dependencies.module.orders_rds.aws_rds_cluster.this`

Intent UNKNOWN: decision requires evidence. No applications file was given, so no RTO or RPO is stated. The availability-zone and metro placement of the target are NOT_ASSESSED: this build holds no evidence for them.

| Fact | As the source states it | What it is not |
|---|---|---|
| availability zone | not stated in the source | an absent zone is not read as a default zone |
| contract item backup-retention | observed yes; disposition LEDGER | the state of the contract item, not a setting of the target |
| contract item readable-standbys | observed yes; disposition NOT_APPLICABLE | the state of the contract item, not a setting of the target |

### `module.retail_app_ecs.module.alb.aws_lb.this`

Intent UNKNOWN: decision requires evidence. No applications file was given, so no RTO or RPO is stated. The availability-zone and metro placement of the target are NOT_ASSESSED: this build holds no evidence for them.

| Fact | As the source states it | What it is not |
|---|---|---|
| availability zone | not stated in the source | an absent zone is not read as a default zone |
| contract item cross-zone | observed yes; disposition PRESERVED | the state of the contract item, not a setting of the target |

## Limits

- No unit is called resilient and no resilience intent is chosen: the intent of every unit is UNKNOWN until a person decides it from a stated requirement and the facts of the source.
- No RTO or RPO is defaulted or inferred from a resource name; the requirement is what the applications file states, word for word, or it is not provided.
- The zone facts of the source are read by the AWS placement adapter only; for every other source they are NOT_ASSESSED, which does not mean that the source states none.
- The availability zones and metro placement of the STACKIT target are NOT_ASSESSED: this build holds no evidence for them, so nothing here compares the source with the target.
- A unit is listed when it holds state or states a failure-domain, replication or backup fact; a unit that states none and holds no data is not looked at, and the network a unit stands in (a subnet, a route table, a security group) is not a unit with an intent of its own: 46 of the 52 units present in the source are not listed here, and the block says nothing about them.