| Name | Description | Type | Package | Framework |
| AggregatorUtils | Class | org.apache.giraph.comm.aggregators | Giraph | |
| AllAggregatorServerData | Accepts aggregators and their values from previous superstep from master and workers which own aggregators. | Class | org.apache.giraph.comm.aggregators | Giraph |
| CountingCache | Cache which counts the number of flushes per task id (destination worker id), so we know how many requests were sent to the worker | Class | org.apache.giraph.comm.aggregators | Giraph |
| CountingOutputStream | Wrapper for output stream which keeps the place in the beginning for the count of objects which were written to it | Class | org.apache.giraph.comm.aggregators | Giraph |
| GlobalCommValueOutputStream | reduced values in the form of pair (name, type, value) There are two modes: | Class | org.apache.giraph.comm.aggregators | Giraph |
| OwnerAggregatorServerData | Class for holding aggregators which current worker owns, and aggregating partial aggregator values from workers. | Class | org.apache.giraph.comm.aggregators | Giraph |
| SendGlobalCommCache | Takes and serializes global communication values and keeps them grouped by owner partition id, to be sent in bulk. | Class | org.apache.giraph.comm.aggregators | Giraph |
| WorkerAggregatorRequestProcessor | Interface | org.apache.giraph.comm.aggregators | Giraph | |