Tries all hosts resolved for DNS name

[adiamzn]

Problem

By default the default DNS resolver in InetAddress class may cache ip addresses after successfully connecting for the first time.

This is can be problematic if we expect to be able to connect to more than one IP address behind a DNS name.
For example multiple read replicas behind a common dns name, or a failed host that was replaced and now has a new ip.

Proposed Fixed

When creating connecting to a host using a dns name, try all addresses the DNS server was able to resolve.

[yangbodong22011]

Thanks for you contribution.

This brings almost no performance loss, because java.net.InetAddress#getByName(java.lang.String) also calls java.net.InetAddress#getAllByName(java.lang.String), but gets [0 ] Element, just add the overhead of Collections.shuffle(hosts), but it can be ignored.

     public static InetAddress getByName(String host)
         throws UnknownHostException {
         return InetAddress.getAllByName(host)[0];
     }

Some comments are detailed in the code section.

[adiamzn]

@sazzad16 are there any further changes required?

[sazzad16]

are there any further changes required?

@adiamzn No. We're good for now. Thanks!

We'll ping you in case anything comes up. Have a nice day!

[codecov-commenter]

Codecov Report

Merging #2722 (7d2d30b) into master (9b702b8) will increase coverage by 0.01%.
The diff coverage is 87.50%.

@@             Coverage Diff              @@
##             master    #2722      +/-   ##
============================================
+ Coverage     58.41%   58.42%   +0.01%     
- Complexity     3068     3070       +2     
============================================
  Files           177      177              
  Lines         11011    11024      +13     
  Branches        629      632       +3     
============================================
+ Hits           6432     6441       +9     
- Misses         4361     4364       +3     
- Partials        218      219       +1     

Impacted Files	Coverage Δ
...redis/clients/jedis/DefaultJedisSocketFactory.java	93.42% <87.50%> (-1.82%)	⬇️
...in/java/redis/clients/jedis/ConnectionFactory.java	63.26% <0.00%> (-4.09%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9b702b8...7d2d30b. Read the comment docs.