Before today’s streaming stacks existed, Facebook’s Scribe was one of the first systems that could reliably manage multi-terabyte daily log volumes. Soon after, Apache Flume emerged as an incubator project and quickly became a standard solution for large-scale log transport into Hadoop environments.
Flume introduced a simple, extensible model: sources pull or receive log events, channels buffer them reliably and sinks deliver them into storage systems such as HDFS. For the Hadoop era, this was a breakthrough—fully open source, fast, resilient and without any proprietary dependencies.
Simplifying Deployment in Early Hadoop Clusters
Users of the Cloudera Distribution could install the full Flume stack via:
yum install flume-master
yum install flume-node
Flume supported several input mechanisms:
- Plain text file ingestion
- Tail-following for rolling logs
- Syslog over UDP or TCP
- Synthetic or test event sources
Example Architecture: 100-Node Web Cluster
Imagine a large web farm producing hundreds of megabytes of raw logs per minute. Flume agents collect the incoming logs, buffer them and forward the events to Flume collectors. The collectors compress, sort and write the log batches into HDFS—with a well-defined directory layout based on time.
Sample Flume Configuration (Historical Format)
collector1.local : autoCollectorSource | collectorSink(
"hdfs://namenode.local:9000/user/flume/weblogs/%Y-%m-%d/%H00/%M/",
"%{host}-"
);
collector2.local : autoCollectorSource | collectorSink(
"hdfs://namenode.local:9000/user/flume/weblogs/%Y-%m-%d/%H00/%M/",
"%{host}-"
);
collector3.local : autoCollectorSource | collectorSink(...);
collector4.local : autoCollectorSource | collectorSink(...);
agent1.local : syslogTcp("19800") | autoE2EChain;
agent2.local : syslogTcp("19800") | autoE2EChain;
The autoE2EChain provided an automatic failover path: if a collector became unresponsive, the chain reordered the routing priority.
The Flume master UI visualized these logical mappings.
Inspecting Agent State
Every agent maintained internal directories indicating event state:
# cd /tmp/flume/agent/agent1.local/
# ls
done logged sending sent writing
Active log files being written appeared in writing/:
-rw-r--r-- 1 flume flume 418M log.00000019.20111011-162503316+0200.seq
Collector Processing and HDFS Delivery
Collectors compressed batches and stored them in minute-sized partitions in HDFS. Bzip2 was widely used due to its block-marker structure, which allows parallelization and efficient splitting.
# tail -f -n 10 /var/log/flume/*.log
... Creating compressed HDFS file ...
... Finishing checksum group ...
... moved from partial to complete ...
... Closing HDFS file ...
This pipeline reliably produced compressed, time-partitioned, host-tagged log files—a pattern still used by modern data platforms.
How This Maps to Modern Systems
Although today we rely on Kafka, Fluent Bit, Vector, Iceberg ingest pipelines and cloud-native collectors, the architectural principles remain identical: high-throughput ingestion, buffering for durability, structured partitioning and reliable delivery into analytical storage.
Flume represents one of the foundational steps in the evolution of distributed log ingestion.
References
[1] Apache Flume Documentation
[2] Cloudera Flume Installation Guide
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