我有两个模式:
方案1(旧方案):
{
"namespace": "com.org.package",
"type": "record",
"name": "EventModel",
"fields": [
{
"name":"name",
"type":"string"
},
{
"name":"id",
"type":"long"
}
]
}
我用一个布尔字段更新了架构:
方案2(新方案):
{
"namespace": "com.org.package",
"type": "record",
"name": "EventModel",
"fields": [
{
"name":"name",
"type":"string"
},
{
"name":"id",
"type":"long"
},
{
"name":"isActive",
"type":"boolean",
"default":false
}
]
}
kafka主题包含属于旧模式(schema1)的消息。更新使用者架构后,使用者即使在updated字段中存在默认值,也无法反序列化旧的架构消息。
根据avro文件:
if the reader's record schema has a field that contains a default value, and writer's schema does not have a field with the same name, then the reader should use the default value from its field.
if the reader's record schema has a field with no default value, and writer's schema does not have a field with the same name, an error is signalled.
avro文件
反序列化时出现以下错误:
java.io.EOFException: null
at org.apache.avro.io.BinaryDecoder.readBoolean(BinaryDecoder.java:140) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.io.ValidatingDecoder.readBoolean(ValidatingDecoder.java:77) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.generic.GenericDatumReader.readWithoutConversion(GenericDatumReader.java:194) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.specific.SpecificDatumReader.readField(SpecificDatumReader.java:136) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:237) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.specific.SpecificDatumReader.readRecord(SpecificDatumReader.java:123) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.generic.GenericDatumReader.readWithoutConversion(GenericDatumReader.java:170) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:151) ~[avro-1.9.1.jar!/:1.9.1]
at org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:144) ~[avro-1.9.1.jar!/:1.9.1]
当记录缺少字段时,为什么默认值不应用于使用者?非常感谢您的帮助。提前谢谢!
1条答案
按热度按时间kmynzznz1#
尝试将类型更改为
boolean
以及null
为了isActive
而不仅仅是boolean
. 比如:它将使模式向后兼容。