Use higher maxQueriesPerResolve and make exception message more clear.

Motivation:

We use a default of 3 for maxQueriesPerResolve when using the DnsNameResolverBuilder, which is too low if you want to resolve a hostname that uses a lot of CNAME records.

Modifications:

- Use higher default (16)
- Make exception message more clear why it failed.

Result:

Be able to resolve more domains by default and be able to better trouble shoot why a resolver failed.
This commit is contained in:
Norman Maurer 2016-05-27 21:34:36 +02:00
parent 584fbac6ed
commit ee5969edfd
2 changed files with 14 additions and 16 deletions

View File

@ -48,7 +48,7 @@ public final class DnsNameResolverBuilder {
private long queryTimeoutMillis = 5000;
private InternetProtocolFamily[] resolvedAddressTypes = DnsNameResolver.DEFAULT_RESOLVE_ADDRESS_TYPES;
private boolean recursionDesired = true;
private int maxQueriesPerResolve = 3;
private int maxQueriesPerResolve = 16;
private boolean traceEnabled;
private int maxPayloadSize = 4096;
private boolean optResourceEnabled = true;

View File

@ -412,25 +412,23 @@ abstract class DnsNameResolverContext<T> {
final int tries = maxAllowedQueries - allowedQueries;
final StringBuilder buf = new StringBuilder(64);
buf.append("failed to resolve ");
buf.append(hostname);
buf.append("failed to resolve '")
.append(hostname).append('\'');
if (tries > 1) {
buf.append(" after ");
buf.append(tries);
if (trace != null) {
buf.append(" queries:");
buf.append(trace);
if (tries < maxAllowedQueries) {
buf.append(" after ")
.append(tries)
.append(" queries ");
} else {
buf.append(" queries");
buf.append(". Exceeded max queries per resolve ")
.append(maxAllowedQueries)
.append(' ');
}
}
} else {
if (trace != null) {
buf.append(':');
buf.append(trace);
buf.append(':')
.append(trace);
}
}
final UnknownHostException cause = new UnknownHostException(buf.toString());
resolveCache.cache(hostname, cause, parent.ch.eventLoop());