Overview
The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using a simple programming model.
It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-avaiability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-availabile service on top of a cluster of computers, each of which may be prone to failures.
This bundle provides a complete deployment of the core components of the Apache Bigtop platform to perform distributed data analytics at scale. These components include:
- NameNode (HDFS)
- ResourceManager (YARN)
- Slaves (DataNode and NodeManager)
- Client (Bigtop hadoop client)
- Plugin (subordinate cluster facilitator)
Deploying this bundle gives you a fully configured and connected Apache Bigtop cluster on any supported cloud, which can be easily scaled to meet workload demands.
Deploying this bundle
In this deployment, the aforementioned components are deployed on separate units. To deploy this bundle, simply use:
juju quickstart bigtop-processing-mapreduce
See juju quickstart --help
for deployment options, including machine
constraints and how to deploy a locally modified version of bundle.yaml
.
The default bundle deploys three slave nodes and one node of each of the other services. To scale the cluster, use:
juju add-unit slave -n 2
This will add two additional slave nodes, for a total of five.
Status and Smoke Test
The services provide extended status reporting to indicate when they are ready:
juju status --format=tabular
This is particularly useful when combined with watch
to track the on-going
progress of the deployment:
watch -n 0.5 juju status --format=tabular
The charms for each master component (namenode, resourcemanager)
also each provide a smoke-test
action that can be used to verify that each
component is functioning as expected. You can run them all and then watch the
action status list:
juju action do namenode/0 smoke-test
juju action do resourcemanager/0 smoke-test
watch -n 0.5 juju action status
Eventually, all of the actions should settle to status: completed
. If
any go instead to status: failed
then it means that component is not working
as expected. You can get more information about that component's smoke test:
juju action fetch <action-id>
Monitoring
This bundle includes Ganglia for system-level monitoring of the namenode, resourcemanager, and slave units. Metrics are sent to a central ganglia unit for easy viewing in a browser. To view the ganglia web interface, first expose the service:
juju expose ganglia
Now find the ganglia public IP address:
juju status ganglia
The ganglia web interface will be available at:
http://GANGLIA_PUBLIC_IP/ganglia
Benchmarking
This charm provides several benchmarks to gauge the performance of your environment.
The easiest way to run the benchmarks on this service is to relate it to the Benchmark GUI. You will likely also want to relate it to the Benchmark Collector to have machine-level information collected during the benchmark, for a more complete picture of how the machine performed.
However, each benchmark is also an action that can be called manually:
$ juju action do resourcemanager/0 nnbench
Action queued with id: 55887b40-116c-4020-8b35-1e28a54cc622
$ juju action fetch --wait 0 55887b40-116c-4020-8b35-1e28a54cc622
results:
meta:
composite:
direction: asc
units: secs
value: "128"
start: 2016-02-04T14:55:39Z
stop: 2016-02-04T14:57:47Z
results:
raw: '{"BAD_ID": "0", "FILE: Number of read operations": "0", "Reduce input groups":
"8", "Reduce input records": "95", "Map output bytes": "1823", "Map input records":
"12", "Combine input records": "0", "HDFS: Number of bytes read": "18635", "FILE:
Number of bytes written": "32999982", "HDFS: Number of write operations": "330",
"Combine output records": "0", "Total committed heap usage (bytes)": "3144749056",
"Bytes Written": "164", "WRONG_LENGTH": "0", "Failed Shuffles": "0", "FILE:
Number of bytes read": "27879457", "WRONG_MAP": "0", "Spilled Records": "190",
"Merged Map outputs": "72", "HDFS: Number of large read operations": "0", "Reduce
shuffle bytes": "2445", "FILE: Number of large read operations": "0", "Map output
materialized bytes": "2445", "IO_ERROR": "0", "CONNECTION": "0", "HDFS: Number
of read operations": "567", "Map output records": "95", "Reduce output records":
"8", "WRONG_REDUCE": "0", "HDFS: Number of bytes written": "27412", "GC time
elapsed (ms)": "603", "Input split bytes": "1610", "Shuffled Maps ": "72", "FILE:
Number of write operations": "0", "Bytes Read": "1490"}'
status: completed
timing:
completed: 2016-02-04 14:57:48 +0000 UTC
enqueued: 2016-02-04 14:55:14 +0000 UTC
started: 2016-02-04 14:55:27 +0000 UTC
Deploying in Network-Restricted Environments
Charms can be deployed in environments with limited network access. To deploy in this environment, you will need a local mirror to serve required packages.
Mirroring Packages
You can setup a local mirror for apt packages using squid-deb-proxy. For instructions on configuring juju to use this, see the Juju Proxy Documentation.