how to solve Waiting for next available executor jenkins

 issue:

got message 

Waiting for next available executor

and it hanpped about 5 minutes , when executing something

solution :

increase executor on on menu 

Manage Jenkins > Manage Nodes and cloud > master-node > configure 

by default executor is only 2 but I increase it until 20 and it work again

this config will impact on memory usage when many executor run