Pilot Map Reduce

Distributed map-reduce over agent swarms for parallel data processing. Use this skill when: 1. You need to process large datasets across multiple workers 2. You want parallel map phase followed by aggregating reduce phase 3. You have embarrassingly parallel tasks with combine step Do NOT use this skill when: - Tasks are not parallelizable (use single worker) - You need streaming results (use pilot-load-balancer)

Implement distributed map-reduce patterns for parallel data processing across agent swarms.

Commands

Submit map tasks to workers

bash

TOTAL_WORKERS=$(pilotctl --json peers --search "role:mapper" | jq 'length')

for i in $(seq 0 $((TOTAL_WORKERS - 1))); do
  WORKER=$(pilotctl --json peers --search "role:mapper" | jq -r ".[$i].address")

  pilotctl --json send-message "$WORKER" \
    --data "{\"type\":\"map_task\",\"job_id\":\"$JOB_ID\",\"chunk_start\":$((i * 1000)),\"chunk_end\":$(((i + 1) * 1000))}"
done

Collect map results

bash

EXPECTED_RESULTS=$TOTAL_WORKERS
RECEIVED=0

while [ $RECEIVED -lt $EXPECTED_RESULTS ]; do
  RESULTS=$(pilotctl --json received \
    | jq '[.messages[] | select(.payload.type == "map_result" and .payload.job_id == "'$JOB_ID'")] | length')
  RECEIVED=$RESULTS
  sleep 1
done

Shuffle and reduce

bash

MAP_RESULTS=$(cat /tmp/map-results-$JOB_ID.json)
KEYS=$(echo "$MAP_RESULTS" | jq -r '.[].payload.results | to_entries | .[].key' | sort -u)

for key in $KEYS; do
  VALUES=$(echo "$MAP_RESULTS" | jq -r '[.[].payload.results."'$key'" // empty] | flatten')

  pilotctl --json send-message "$REDUCER" \
    --data "{\"type\":\"reduce_task\",\"job_id\":\"$JOB_ID\",\"key\":\"$key\",\"values\":$VALUES}"
done

Workflow Example

Word count across distributed text corpus:

bash

#!/bin/bash
JOB_ID="wordcount-$(date +%s)"

# MAP phase
MAPPERS=$(pilotctl --json peers --search "role:mapper" | jq -r '.[].address')
for i in $(seq 0 9); do
  pilotctl --json send-message "${MAPPERS[$i]}" \
    --data "{\"type\":\"map_task\",\"job_id\":\"$JOB_ID\",\"chunk\":$i}" &
done
wait

# REDUCE phase
sleep 5
MAP_RESULTS=$(pilotctl --json received \
  | jq '[.messages[] | select(.payload.type == "map_result")]')

FINAL=$(echo "$MAP_RESULTS" | jq 'map({(.payload.word): .payload.count}) | add')
echo "$FINAL"

Dependencies

Requires pilot-protocol skill, jq, and sort.