Bigtable distributed storage system

论文原文

Bigtable presents a multi-dimensional sorted map to users.
● Keys are (row, column, time stamp).
● Handles petabytes of data and runs reliably on large numbers of (possibly unreliable) machines.
● Provides lookup and update operations on each row, and
● Provides atomic read-modify-write operations on individual rows (but not multiple rows).
● A running Bigtable consists of a collection of tablet servers, each of which is responsible for serving several tablets
● (tablet = contiguous region of key space).
● The operation of the tablet servers is coordinated by a master, i.e., the master might direct a server to load/unload a tablet.
● A tablet is stored as a collection of readonly files in the Google SSTable (Sorted String Table) format.
● The SSTables are stored in GFS, and Bigtable relies on GFS to preserve data in the event of disk loss

.compactUnderscore.js

.compact([0, 1, false, 2, ‘’, 3]);
=> [1, 2, 3]

.compact([0, 1, false, 2, ‘’, 3]);
=> [1, 2, 3]

ls /home/alex/dir