3 ms·
Thank you for raising these relevant points. They led me down a fascinating rabbit hole on this topic of "database as file system". This is way over my head, bu
by lioeters 7y ago
Thank you for raising these relevant points. They led me down a fascinating rabbit hole on this topic of "database as file system". This is way over my head, but to pique others' curiosity, here's the abstract:
Recent improvements in both the performance and scalability of shared-nothing, transactional, in-memory NewSQL databases have reopened the research question of whether distributed metadata for hierarchical file systems can be managed using commodity databases.
In this paper, we introduce HopsFS, a next generation distribution of the Hadoop Distributed File System (HDFS) that replaces HDFS’ single node in-memory metadata service, with a distributed metadata service built on a NewSQL database.
By removing the metadata bottleneck, HopsFS enables an order of magnitude larger and higher throughput clusters compared to HDFS. Metadata capacity has been increased to at least 37 times HDFS’ capacity, and in experiments based on a workload trace from Spotify, we show that HopsFS supports 16 to 37 times the throughput of Apache HDFS. HopsFS also has lower latency for many concurrent clients, and no downtime during failover. Finally, as metadata is now stored in a commodity database, it can be safely extended and easily exported to external systems for online analysis and free-text search.
- daviesliu 7y agoHave you publish the workload tracing from Spotify? We are very interesting on the results you got, looking for a way to replicate that using our setup.
- jamesblonde 7y agoThe workload isn't public, but if you follow the same ratio of FS operations (60+% getBlockLocations (file stat), etc), you will get similar results. You can even assume that operations follow that distribution uniformly, although there will be bursts of different op types - in the paper, we added microbenchmarks for each FS operation to show their load on the system. That distribution is in the paper and Salman's thesis.