API (Application Programming Interface)#

The program interface of an app through which one program can interact with another.


Checks a request, response, or URL for compliance with specified conditions, for example, the presence of the string in the response.For more information, see Configure assertions.


Pieces of text sent to your browser by a website you visit. Websites use cookies to identify unique users across browsing sessions. For more information, see Set default cookies.

Correlation of a parameter#

Dynamic parameterization of data, in which internal identifiers that define the execution context must be replaced with variables that will take correct values from startup to startup, extracted from responses to requests to the system. For example, there was a user ID received at login, which must be presented in all subsequent transactions. For more information, see Requests correlation.

CSV parameter#

A parameter that’s dynamically changed based on the values prepared in advance in the CSV file. For more information, see Add a CSV parameter.


A tool integrated into PFLB Platform and used to visualize load test data. You can use Grafana to graphically represent time series and text data. For more information, see Grafana documentation.


Hierarchically ordered set of elements describing the execution of a single atomic test scenario (Use Case). The group can include transactions, HTTP requests and logical elements such as conditions and loops. Logical elements allow you to customize the variability of the test scenario. Transactions send HTTP requests during test execution in the specified order.For more information, see Create a group.


An open source framework for remote procedure calls. HTTP/2 is used as the transport, and Protocol Buffers is used as the interface description language. For more information, see Add and edit gRPC requests.

HAR (HTTP Archive format)#

HTTP archive or log file of network requests to the system in JSON format. For more information, see Import requests from HAR, Insomnia, Postman.


Messages that are sent by a client to a server to trigger some actions to be performed. For example, to get access to a certain resource.For more information, see HTTP requests.

Load profile#

A set of operations with specified intensities, received on the basis of statistical data collection or determined by analyzing the requirements for the testing system.

Percentile 95#

A statistical measure indicating the value that a given random variable doesn’t exceed with a specified probability. For example, the percentile 95 equal to “X” means that 95% of the system response times to a request or transaction doesn’t reach the value of “X” and only 5% of the response times exceed this value.

PFLB chart#

A report block, a graph to display the metrics of one or more test runs.For more information, see Create a PFLB chart.

PFLB table#

A report block, a table with SLA metrics values per request, test, or transaction.For more information, see Create a PFLB table.

Settings set#

Pre-created test’s settings that you can reuse in different tests. For more information, see Add a settings set.

SLA (service-level agreement)#

Non-functional requirements that determine the criteria for the success of the performed tests. For more information, see Configure SLA.


Timeout before sending a request by virtual users to the testing system. For more information, see Configure timers.


A set of user actions grouped together to measure time, which represent the actual user actions in the app. A transaction can contain several requests or a sequence of actions that arrive at the server with the specified metrics (SLA). Transactions send HTTP requests during test execution in the specified order.

Trend report#

A report that’s created based on the results of two or more load test runs and allows you to analyze the trend of changes in the parameters of the testing system. The results are displayed in tables and graphs. For more information, see Create trend reports.

Virtual user (VUser)#

A separate working thread of a load tool that emulates the operation of a business process from the user.


Sending notifications when the test status changes, for example, when it’s finished. You can use webhooks as triggers in CI/CD pipelines. For more information, see Add a settings set.