How to query kafka streams state store correctly? - apache-kafka

Question

I have built a kafka-streams application with 20 streams threads a month ago. This app calculates the consumption of different people in a fixed time interval. Recently I found the people's spend money that is queried form local state store is less than real. I have read official, and any other documents I could find, but have not found the solve method.
I used Kafka version 0.11.0.3, kafka server's version is 0.11.0.3, and kafka streams api is also 0.11.0.3. Only one application with 20 streams threads.
Some important info:
Kafka streams config:
replication.factor 3
num.stream.threads 20
commit.interval.ms 1000
partition.assignment.strategy StickyAssignor.class.getName()
fetch.max.wait.ms 500
max.poll.records 5000
max.poll.interval.ms 300000
heartbeat.interval.ms 3000
session.timeout.ms 30000
auto.offset.reset latest
kafka message structure
key = person's name
value = the money he spend
time = the current time that this message was created
Kafka streams build code:
KStreamBuilder kStreamBuilder = new KStreamBuilder();
KStream<String, Double> peopleSpendStream = kStreamBuilder.stream(topic);
peopleSpendStream.groupByKey()// group by people's name
.aggregate(() -> new HashMap<String, Double>(8192),
(key, value, aggregate) -> {
aggregate.merge(key, value, Double::sum);
return aggregate;
},
TimeWindows.of(ONE_MINUTE).until(ONE_HOUR * 10), // 1-min window, keep 9 hours
new HashMapSerde<>(), // serialize and deserialize by jackson actually
PEOPLE_SPEND_STORE_NAME);
Query code:
long time = System.currentTimeMilles();
for (String name : names) { // query by people's name
try (WindowStoreIterator<HashMap<String, Double>> iterator = store.fetch(name, time - TEN_MINUTE_MILLES, time)) {
iterator.forEachRemaining(kv -> log.info("name = {}, time = {}, cost = {}", name, kv.key, kv.value));
}
}
Is anything I get wrong? I need your help in particular.