Synthetic jobs are configurable, scheduled tests that mimic end-user actions in remote browsers in supported locations. Synthetic jobs consist of URL measurements or synthetic scripts. To create a job, see Get Started with Browser Synthetic Monitoring.  

Synthetic Job Support

This table describes supported versions and libraries for Synthetic Jobs.

Support TypeDescription
Browser Versions
  • IE 11
  • Chrome 81.0.4044.0
  • Firefox 72
Python Versions
  • Python 2
  • Python 3
Python Libraries

Synthetic Job Locations

For URL measurements and synthetic script jobs, the Synthetic Agent is always executed in isolation within a Docker container. This location is then mapped to the configured browser location. The synthetic script, however, is run on a different machine or location from the configured browser for security reasons. See Synthetic Agent Locations.

Synthetic Job Queue

When you create a synthetic job, it is added to a queue based on the creation timestamp. Scheduled jobs are assigned a maturity level that influences when they will be executed in the synthetic job queue.

Maturity Level for Scheduled Jobs

Scheduled jobs are assigned a maturity level based on creation time and added to the synthetic job queue. This table describes the two supported maturity levels.

Maturity LevelDescription
Junior

The Junior maturity level consists of synthetic jobs that are created or updated within two hours. Once two hours have passed since the last update or creation of the job, the Junior job maturity level is promoted to Senior maturity level. The promotion from Junior to Senior maturity is only performed only if enough capacity has been allocated. This avoids negatively affecting jobs which are currently executing.

SeniorThe Senior maturity level consists of synthetic jobs that have been created or updated more than two hours ago. Synthetic jobs with Senior maturity level have ample allocated resources to be executed.

Job Execution Order

The execution order of synthetic jobs depends on the job priority and the job creation time. Synthetic jobs are only executed if they are in the job queue. Job priority is based on several factors: job type, job maturity, and your Browser Synthetic Monitoring license. The table below shows how the job priority is calculated. The actual job execution order depends on the job priority and job creation timestamp. 

Synthetic jobs are only executed if they are in the job queue. If the max job queue size has been reached, however, no additional synthetic jobs will be added to the queue until the queue size decreases. The max queue size is defined by the priority, license, type, and maturity level.

QueueJob TypeJob Seniority
High-priorityScheduledSenior
On-demandN/A
Low-priorityScheduledJunior

Synthetic Job Execution Cadence

The synthetic job scheduler executes jobs according to these cron-based expression:

<second> <minute> <hour> <day-of-month> <month> <day-of-week> <year>

When you schedule a job, you choose how frequently the job runs. It is recommended you choose a larger unit of time (hours or days) that can evenly divide into the smaller unit of time (minutes or hours). For example, if a job is scheduled to run every 15 minutes, the job runs four times within the hour. This results in the job consistently repeating every hour without interruption to the schedule.

However, if you schedule a job such that a larger unit of time that does not divide evenly into the smaller unit of time, such as running every 50 minutes, then the job does not run at consistent times. For example, if the first job starts at 7:03, then the job will run at 7:53, 8:03, 8:53, and so on, resulting in a disruption to the schedule.

Job Execution Errors

This table provides job execution error messages, the cause of the error, and the associated error code. 

Error MessageCause of ErrorError Code
Skipped; still waiting for a previous job executionAn attempt was made to queue a high-priority measurement request from a scheduled job before the previous measurement request from the same job, and location-browser combination has been processed.TARDY
Skipped while new capacity is being addedAn attempt was made to queue a low-priority measurement request from a scheduled job before the previous measurement request from the same job, and location-browser combination has been processed.TARDY_ONBOARDING
Skipped while new capacity is being addedAn attempt was made to queue a measurement request from a junior job beyond the maximum respective queue capacity.ONBOARDING
Testing location is overloadedAn attempt was made to request measurement from a senior job beyond the maximum respective queue capacity.THROTTLED