public enum TopicOverloadPolicy extends Enum<TopicOverloadPolicy>
This policy can only be used in combination with the
The reliable topic uses a
store the messages. A ringbuffer doesn't track where readers are, so
it has no concept of a slow consumers. This provides many advantages like
high performance reads, but it also gives the ability to the reader to
re-read the same message multiple times in case of an error.
A ringbuffer has a limited, fixed capacity. A fast producer may overwrite
old messages that are still being read by a slow consumer. To prevent
this, we may configure a time-to-live on the ringbuffer (see
Once the time-to-live is configured, the
controls how the publisher is going to deal with the situation that a
ringbuffer is full and the oldest item in the ringbuffer is not old
enough to get overwritten.
Keep in mind that this retention period (time-to-live) can keep messages from being overwritten, even though all readers might have already completed reading.
|Enum Constant and Description|
The caller will wait till there space in the ringbuffer.
The message that was to be published is discarded.
Using this policy, a message that has not expired can be overwritten.
The publish call immediately fails.
|Modifier and Type||Method and Description|
Returns the enum constant of this type with the specified name.
Returns an array containing the constants of this enum type, in the order they are declared.
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf
public static final TopicOverloadPolicy DISCARD_OLDEST
This can be a problem for slow consumers because they were promised a certain time window to process messages. But it will benefit producers and fast consumers since they are able to continue. This policy sacrifices the slow producer in favor of fast producers/consumers.
public static final TopicOverloadPolicy DISCARD_NEWEST
public static final TopicOverloadPolicy BLOCK
public static final TopicOverloadPolicy ERROR
public static TopicOverloadPolicy values()
for (TopicOverloadPolicy c : TopicOverloadPolicy.values()) System.out.println(c);
public static TopicOverloadPolicy valueOf(String name)
name- the name of the enum constant to be returned.
IllegalArgumentException- if this enum type has no constant with the specified name
NullPointerException- if the argument is null
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