# MCP Server End-to-End Availability Calculator

> Source: https://netray.co/tools/mcp-server-end-to-end-availability-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Multiplies component uptimes in the agent request path and shows downtime per month, with a replica what-if for the MCP server.

## Category

developer

## Audience

- Platform engineer
- AI engineer
- IT manager

## Tool

**Kind:** calculator

**Inputs:**

#### MCP server instance availability

**Key:** mcp

**Type:** number

**Default:** 99.5

**Min:** 90

**Max:** 100

**Step:** 0.05

**Unit:** %

#### Active replicas of the MCP server

**Key:** replicas

**Type:** slider

**Default:** 1

**Min:** 1

**Max:** 5

**Step:** 1

**Unit:** replicas

**Help:** Assumes independent failures behind a load balancer.

#### ERP API availability

**Key:** erp

**Type:** number

**Default:** 99.5

**Min:** 90

**Max:** 100

**Step:** 0.05

**Unit:** %

#### Identity provider availability

**Key:** idp

**Type:** number

**Default:** 99.9

**Min:** 90

**Max:** 100

**Step:** 0.05

**Unit:** %

#### Model endpoint availability

**Key:** llm

**Type:** number

**Default:** 99.5

**Min:** 90

**Max:** 100

**Step:** 0.05

**Unit:** %

#### Days in period

**Key:** days

**Type:** number

**Default:** 30

**Min:** 1

**Max:** 365

**Step:** 1

**Unit:** days

**Outputs:**

#### MCP tier availability with replicas

**Key:** mcp_eff

**Expr:** 100 * (1 - pow(1 - mcp / 100, replicas))

**Format:** percent

#### End-to-end availability

**Key:** overall

**Expr:** mcp_eff * erp * idp * llm / 1000000

**Format:** percent

**Primary:** true

#### Expected downtime in period

**Key:** down_min

**Expr:** (1 - overall / 100) * days * 1440

**Format:** minutes

**Primary:** true

#### Expected downtime in hours

**Key:** down_h

**Expr:** down_min / 60

**Format:** hours

#### Weakest component availability

**Key:** weakest

**Expr:** min(min(mcp_eff, erp), min(idp, llm))

**Format:** percent

**Chart:**

#### End-to-end availability by MCP replica count

**Type:** line

**X:** replicas

**From:** 1

**To:** 5

**Steps:** 5

**Series:**

- overall

**Disclaimer:** Assumes independent failures and all components required for every request. Correlated failures, shared hosts and maintenance windows make real availability lower.

## Content

**Intro:** An agent answer needs the identity provider, the MCP server, the ERP API and the model to all be up. Their availabilities multiply, so the chain is weaker than any single link.

**Sections:**

#### How to use it

**Body:** Enter each component's availability as a percentage from your monitoring or contract. Use measured values where you have them rather than the vendor's marketing figure. Set the number of active MCP replicas to see the effect of redundancy at that tier. The outputs give end-to-end availability, expected downtime in the period and the weakest link. The chart sweeps replicas from one to five and shows how quickly redundancy helps the one tier you control.

#### Formula

**Body:** For components in series, availability is the product of the individual availabilities. For n independent active replicas, tier availability is one minus (one minus a) to the power n. Downtime equals (1 minus overall) times the minutes in the period. Four components at 99.5, 99.5, 99.9 and 99.5 percent combine to about 98.4 percent, which is roughly eleven hours of downtime a month, much worse than any single figure suggests.

**Bullets:**

- Replicas fix only the tier they sit on.
- Shared database or host breaks independence.
- Graceful degradation, such as cached answers, changes the model.

#### Using the result

**Body:** If the total is below what users need, find the weakest link first. Often it is the ERP, which you cannot replicate, so add read replicas or cached views for read-only agent queries. Self-hosting the model removes an external dependency but adds your own GPU availability to the chain. Document which failures should produce a clear error message rather than a silent wrong answer.

**Cta:** Netray designs on-prem agent stacks with read-only ERP access and fallbacks. We can help set realistic availability targets for your stack.

**Faq:**

#### Why is combined availability lower than each part?

**Answer:** Because a request succeeds only if every required component is up at that moment. Independent failures accumulate, so the probabilities multiply, and the product is always lower than the weakest single value.

#### Do replicas always help?

**Answer:** Only if failures are independent. Replicas on one host, one database or one deployment pipeline share failure modes. Spread across nodes and avoid shared single points to see the computed benefit.

#### What does 99.9 percent mean per month?

**Answer:** About 43 minutes of downtime in a 30 day month. 99.5 percent allows about three and a half hours, and 99 percent about seven hours. Use the downtime output for your own period.

#### Should I include planned maintenance?

**Answer:** Yes if it makes the service unavailable to users. Either reduce the stated availability by the maintenance share or schedule it outside business hours and report availability for working hours.

## Search terms

mcp server availability, composite sla calculator, serial availability calculation, agent uptime calculator, combined uptime of dependencies, monthly downtime from availability

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