The performance test metrics are plotted in one-minute increments. All of the load generating servers feed data back to the LoadStorm reporting engine.
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Volume graphs show the traffic measurements between LoadStorm and the target web application. Basically, how strong is the storm?
The Summary graph shows high-level metrics of how the target web application performed. It includes a combination of performance metrics.
Summary metrics:
- Requests per Second
- Concurrent Users
- Peak Response Time – Time to get slowest resource
- Throughput – Kilobytes per Second
- Errors
- Average Response Time – Average time to get site’s resources
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Response Time Distribution graphs show the spread of response time data in a graph. This is the range of wait times that your end user could be experiencing. Use this graph to sort out your outliers from your true test data.
Response metrics:
- Min/Max – Highest and lowest response times at that point of the test
- 90% (1.28 σ) – Response times within the 90th percentile (1.28 standard deviations)
- 68% (1 σ) – Response times within the 68th percentile (1 standard deviation)
- Average (μ)
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Finally, Error graphs show the percentage of errors reported during a test. These are the types of problems the VUsers are experiencing. Find out when certain error types become a problem as your site scales. Below are just a handful of the errors we catch.
Error Types
- 401: Unauthorized – A VUser failed authentication to access the target server.
- 403: Forbidden – A VUser couldn’t get to a resource.
- 404: Not Found – Usually the link is invalid due to a typo, permissions, or the file does not exist.
- 500: Internal Server Error – Likely an issue with your server. Does it look like it’s about to crash?
- 502: Bad Gateway – Issue with target servers.
- 503: Service Unavailable – Your server is barely functioning, and can only respond with this status code.
- Request Read Timeout – Resources are taking too long to load, but timeouts are customizable.
- Request Connection Timeout – Our engines can’t establish a connection to the target server.
- Socket Connection Timeout – We barely couldn’t establish a connection to the target server.