Metadata Store Key was changed so that it is not compatible with 2.7.1.

The code is in org.apache.dubbo.metadata.identifier.MetadataIdentifier
}
    public String getVersion() {
        return version;
    }
    public void setVersion(String version) {
        this.version = version;
    }
    public String getGroup() {
        return group;
    }
    public void setGroup(String group) {
        this.group = group;
    }
    public String getSide() {
        return side;
    }
    public void setSide(String side) {
        this.side = side;
    }
    public String getApplication() {
        return application;
    }
    public void setApplication(String application) {
        this.application = application;
    }
    public static enum KeyTypeEnum {
        PATH, UNIQUE_KEY
    }
}