Merge pull request jhuangtw#90 from unixorn/add-moosefs

Add link to MooseFS open-source distributed filesystem

README.md

@@ -36,7 +36,7 @@ See also: [System Design Primer](https://github.com/donnemartin/system-design-pr
 
 | Google Internal                          | Google External                          | Open Source / Real-World                 |
 | ---------------------------------------- | ---------------------------------------- | ---------------------------------------- |
-| GFS/Colossus                             |                                          | HDFS, [Ceph](https://ceph.com), [GlusterFS](https://www.gluster.org) |
+| GFS/Colossus                             |                                          | HDFS, [Ceph](https://ceph.com), [GlusterFS](https://www.gluster.org), [MooseFS](https://moosefs.com/products/#moosefs) |
 | BigTable                                 | [Cloud BigTable](https://cloud.google.com/bigtable) | [PrestoDB](https://prestodb.io/), [Cassandra](https://github.com/apache/cassandra), [HBase](https://github.com/apache/hbase), [Accumulo](https://github.com/apache/accumulo), [DynamoDB](https://aws.amazon.com/dynamodb), [ScyllaDB](https://www.scylladb.com/) |
 | [Spanner](http://research.google.com/archive/spanner.html) | [Cloud Spanner](https://cloud.google.com/spanner/) | [Vitess](https://vitess.io), [CockroachDB](https://github.com/cockroachdb/cockroach), [TiDB](https://github.com/pingcap/tidb) |
 | ColumnIO / [Capacitor](https://cloud.google.com/blog/big-data/2016/04/inside-capacitor-bigquerys-next-generation-columnar-storage-format) |                                          | [Apache Parquet](http://parquet.apache.org) |