superfrink/distributed-hash

A distributed hash table written in Go

distributed-hash's Issues

Consider making servers use durable storage.

Currently the server processes only store data in volatile memory.

Add logging to the server.

1. Add logging to a logfile (or syslog?)
2. Remove printing to STDERR and STDOUT (except on failure to start).

hc.conf should not need to be in the current working directory

1. Add a command line flag.
2. Consider defaulting to the current directory and then ~/.hc.conf .

A single command sent in multiple segments is seen as two invalid commands

Consider:

(echo -n "GET" ; echo -n " a") | nc -q1 localhost 1742
(echo -n "GET" ; sleep 1 ; echo -n " a") | nc -q1 localhost 1742

The former works while the latter does not because the server sees two requests: "GET" followed by " a". Neither of which are valid.

Additional requests in a single segment are ignored.

Consider:

(echo 'GET a' ; sleep 1 ; echo 'GET b') | nc -q1 localhost 1742
(echo 'GET a' ; echo 'GET b') | nc -q1 localhost 1742

The former is seen as two GET commands. In the latter case the second GET is discarded in a buffer after the first command is read.

Newlines should be trimmed from requests by the server

A trailing newline in a GET or PUT request is not trimmed by the server so it becomes part of the key or value. This could either be fixed or become a documented part of the network protocol. I lean towards the former because it feels to be the most likely expected behaviour for someone new to the project.

Consider the following output.

$ echo -n 'PUT a 123' | nc -q1 localhost 1742                                   
cmd: PUT                                                                        
key: a                                                                          
val: 123                                                                        

$ echo 'GET a' | nc -q1 localhost 1742                                          
cmd: GET                                                                        
key: a

len: 2
NOTEXISTS

$ echo -n 'GET a' | nc -q1 localhost 1742
cmd: GET
key: a
len: 1
EXISTS 3 123