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8304885: Reuse stale data to improve DNS resolver resiliency

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Reviewed-by: michaelm, dfuchs
This commit is contained in:
Sergey Bylokhov 2023-06-09 23:20:06 +00:00
parent beec734fdd
commit bdd81b3182
16 changed files with 461 additions and 87 deletions
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110
src/java.base/share/classes/sun/net/InetAddressCachePolicy.java
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -27,6 +27,7 @@ package sun.net;
import java.security.PrivilegedAction;
import java.security.Security;
import java.util.concurrent.TimeUnit;
@SuppressWarnings("removal")
public final class InetAddressCachePolicy {
@ -36,6 +37,12 @@ public final class InetAddressCachePolicy {
private static final String cachePolicyPropFallback =
"sun.net.inetaddr.ttl";
// Controls the cache stale policy for successful lookups only
private static final String cacheStalePolicyProp =
"networkaddress.cache.stale.ttl";
private static final String cacheStalePolicyPropFallback =
"sun.net.inetaddr.stale.ttl";
// Controls the cache policy for negative lookups only
private static final String negativeCachePolicyProp =
"networkaddress.cache.negative.ttl";
@ -59,6 +66,15 @@ public final class InetAddressCachePolicy {
*/
private static volatile int cachePolicy = FOREVER;
/* The Java-level namelookup cache stale policy:
*
* any positive value: the number of seconds to use the stale names
* zero: do not use stale names
*
* default value is never (NEVER).
*/
private static volatile int staleCachePolicy = NEVER;
/* The Java-level namelookup cache policy for negative lookups:
*
* -1: caching forever
@ -85,31 +101,7 @@ public final class InetAddressCachePolicy {
* Initialize
*/
static {
Integer tmp = java.security.AccessController.doPrivileged(
new PrivilegedAction<Integer>() {
public Integer run() {
try {
String tmpString = Security.getProperty(cachePolicyProp);
if (tmpString != null) {
return Integer.valueOf(tmpString);
}
} catch (NumberFormatException ignored) {
// Ignore
}
try {
String tmpString = System.getProperty(cachePolicyPropFallback);
if (tmpString != null) {
return Integer.decode(tmpString);
}
} catch (NumberFormatException ignored) {
// Ignore
}
return null;
}
});
Integer tmp = getProperty(cachePolicyProp, cachePolicyPropFallback);
if (tmp != null) {
cachePolicy = tmp < 0 ? FOREVER : tmp;
propertySet = true;
@ -121,40 +113,60 @@ public final class InetAddressCachePolicy {
cachePolicy = DEFAULT_POSITIVE;
}
}
tmp = java.security.AccessController.doPrivileged (
new PrivilegedAction<Integer>() {
public Integer run() {
try {
String tmpString = Security.getProperty(negativeCachePolicyProp);
if (tmpString != null) {
return Integer.valueOf(tmpString);
}
} catch (NumberFormatException ignored) {
// Ignore
}
try {
String tmpString = System.getProperty(negativeCachePolicyPropFallback);
if (tmpString != null) {
return Integer.decode(tmpString);
}
} catch (NumberFormatException ignored) {
// Ignore
}
return null;
}
});
tmp = getProperty(negativeCachePolicyProp,
negativeCachePolicyPropFallback);
if (tmp != null) {
negativeCachePolicy = tmp < 0 ? FOREVER : tmp;
propertyNegativeSet = true;
}
if (cachePolicy > 0) {
tmp = getProperty(cacheStalePolicyProp,
cacheStalePolicyPropFallback);
if (tmp != null) {
staleCachePolicy = tmp;
}
}
}
private static Integer getProperty(String cachePolicyProp,
String cachePolicyPropFallback)
{
return java.security.AccessController.doPrivileged(
new PrivilegedAction<Integer>() {
public Integer run() {
try {
String tmpString = Security.getProperty(
cachePolicyProp);
if (tmpString != null) {
return Integer.valueOf(tmpString);
}
} catch (NumberFormatException ignored) {
// Ignore
}
try {
String tmpString = System.getProperty(
cachePolicyPropFallback);
if (tmpString != null) {
return Integer.decode(tmpString);
}
} catch (NumberFormatException ignored) {
// Ignore
}
return null;
}
});
}
public static int get() {
return cachePolicy;
}
public static int getStale() {
return staleCachePolicy;
}
public static int getNegative() {
return negativeCachePolicy;
}