Commit Graph

6 Commits

Author SHA1 Message Date
Trustin Lee
7e9542edf7 Provide more control over DnsNameResolver.query() / Add NameResolver.resolveAll()
Related issues:
- #3971
- #3973
- #3976
- #4035

Motivation:

1. Previously, DnsNameResolver.query() retried the request query by its
own. It prevents a user from deciding when to retry or stop. It is also
impossible to get the response object whose code is not NOERROR.

2. NameResolver does not have an operation that resolves a host name
into multiple addresses, like InetAddress.getAllByName()

Modifications:

- Changes related with DnsNameResolver.query()
  - Make query() not retry
    - Move the retry logic to DnsNameResolver.resolve() instead.
  - Make query() fail the promise only when I/O error occurred or it
    failed to get a response
  - Add DnsNameResolverException and use it when query() fails so that
    the resolver can give more information about the failure
  - query() does not cache anymore.

- Changes related with NameResolver.resolveAll()
  - Add NameResolver.resolveAll()
  - Add SimpleNameResolver.doResolveAll()

- Changes related with DnsNameResolver.resolve() and resolveAll()
  - Make DnsNameResolveContext abstract so that DnsNameResolver can
    decide to get single or multiple addresses from it
  - Re-implement cache so that the cache works for resolve() and
    resolveAll()
  - Add 'traceEnabled' property to enable/disable trace information

- Miscellaneous changes
  - Use ObjectUtil.checkNotNull() wherever possible
  - Add InternetProtocolFamily.addressType() to remove repetitive
    switch-case blocks in DnsNameResolver(Context)
  - Do not raise an exception when decoding a truncated DNS response

Result:

- Full control over query()
- A user can now retrieve all addresses via (Dns)NameResolver.resolveAll()
- DNS cache works only for resolve() and resolveAll() now.
2015-08-18 17:41:38 +09:00
Trustin Lee
4aa10db9c5 Use InetSocketAddress.getHostName() instead of getHostString()
Related: #3478

Motivation:

DefaultNameResolver uses InetSocketAddress.getHostString() instead of
getHostName(). Because Netty uses the DefaultNameResolver by default and
getHostString() is available only since Java 7, a user cannot use Netty
on Java 6 anymore.

Modifications:

Use InetSocketAddress.getHostName() which is practically same and also
is available in Java 6.

Result:

Netty 4.1 runs on Java 6 again.
2015-03-10 11:45:56 +09:00
Norman Maurer
a0ca605425 [maven-release-plugin] prepare for next development iteration 2015-03-03 08:30:59 -05:00
Norman Maurer
51a90ee2f5 [maven-release-plugin] prepare release netty-5.0.0.Alpha2 2015-03-03 08:27:16 -05:00
Trustin Lee
d7f5353fe8 Fix memory leak in NameResolverGroup
Motivation:

NameResolverGroup uses the EventExecutor specified with getResolver() as
the key of its internal map.  Because the EventExecutor is often a
wrapped one, such as PausibleChannelEventExecutor, which actually is a
wrapper of the same executor, they should instantiate only one
NameResolver.

Modifications:

Unwrap the EventExecutor before using it as the key of the internal map

Result:

Memory leak is gone.
2014-11-20 20:22:17 +09:00
Trustin Lee
fa248cecb5 Name resolver API and DNS-based name resolver
Motivation:

So far, we relied on the domain name resolution mechanism provided by
JDK.  It served its purpose very well, but had the following
shortcomings:

- Domain name resolution is performed in a blocking manner.
  This becomes a problem when a user has to connect to thousands of
  different hosts. e.g. web crawlers
- It is impossible to employ an alternative cache/retry policy.
  e.g. lower/upper bound in TTL, round-robin
- It is impossible to employ an alternative name resolution mechanism.
  e.g. Zookeeper-based name resolver

Modification:

- Add the resolver API in the new module: netty-resolver
- Implement the DNS-based resolver: netty-resolver-dns
  .. which uses netty-codec-dns
- Make ChannelFactory reusable because it's now used by
  io.netty.bootstrap, io.netty.resolver.dns, and potentially by other
  modules in the future
  - Move ChannelFactory from io.netty.bootstrap to io.netty.channel
  - Deprecate the old ChannelFactory
  - Add ReflectiveChannelFactory

Result:

It is trivial to resolve a large number of domain names asynchronously.
2014-10-16 17:10:36 +09:00