Reducing start latency of serverless microservices

A system for reducing start latency of serverless microservices, the system comprising:

• a memory;
• and
• a processor in communication with the memory, the processor being configured to perform operations comprising:
• detecting an incoming request or event to an application in a serverless microservice environment, wherein the incoming request or event initiates simultaneous invocations of one or more microservices of the application;
• monitoring a replica count of an initial microservice, wherein the initial microservice controls the incoming request or event;
• selecting an amount of selected microservices from the one or more microservices of the application by detecting a change in the replica count from zero, wherein the amount of selected microservices perform a task of the incoming request or event, and wherein the task applies one or more predefined application-specific rules to one or more elements of the incoming request or event to determine the amount of selected microservices;
• triggering scaling up activation of the selected microservices in response to determining that the selected microservices are needed for the incoming request, wherein said triggering reduces a cold-start time of the application;
• and
• invoking the selected microservices of the application to match the amount of selected microservices.

A computer program product for reducing start latency of serverless microservices, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processors to perform a function, the function comprising:

• detecting an incoming HTTP request to an application in a serverless microservice environment, wherein the incoming HTTP request initiates simultaneous invocations of one or more microservices of the application;
• monitoring a replica count of an initial microservice, wherein the initial microservice controls the incoming HTTP request;
• selecting an amount of selected microservices from the one or more microservices of the application by detecting a change in the replica count from zero, wherein the amount of selected microservices perform a task of the incoming HTTP request, and wherein the task applies one or more predefined application-specific rules to one or more elements of the incoming HTTP request to determine the amount of selected microservices, and wherein the one or more elements of the incoming HTTP request comprise at least one of an HTTP query parameter or a custom HTTP header;
• triggering scaling up activation of the one or more microservices of the application;
• and
• invoking the one or more microservices of the application to match the amount of selected microservices.