当rsyslog重新启动时，syslog4j停止日志记录。

Question

重新启动rsyslog守护进程之后，syslog4j 0.9.46将无法在不重新启动java进程的情况下成功地写入syslog。没有抛出任何异常，我看不到通过API检查日志是否仍然有效。是否有办法使syslog4j从rsyslog重新启动中恢复，或者至少抛出一个异常，以便可以手动重新启动连接？

样本代码：

import java.util.Scanner;

import org.productivity.java.syslog4j.SyslogConstants;
import org.productivity.java.syslog4j.SyslogIF;
import org.productivity.java.syslog4j.impl.unix.socket.UnixSocketSyslog;
import org.productivity.java.syslog4j.impl.unix.socket.UnixSocketSyslogConfig;


public class SysLogging {

    public static void main(String[] args) {
        UnixSocketSyslogConfig cfg = new UnixSocketSyslogConfig();
        cfg.setFacility(SyslogConstants.FACILITY_LOCAL1);
        cfg.removeAllMessageModifiers();
        cfg.setIdent(null);
        cfg.setThrowExceptionOnWrite(true);
        cfg.setWriteRetries(5);
        SyslogIF log = new UnixSocketSyslog();
        log.initialize(SyslogConstants.UNIX_SOCKET, cfg);

        Scanner scanner = new Scanner(System.in);
        System.out.println("type quit to quit, anything else to log");
        String line = scanner.nextLine();
        while(!line.equals("quit")) {
            log.info(line);
            System.out.println("type quit to quit, anything else to log");
            line = scanner.nextLine();
        }
        scanner.close();
    }
}

在重新启动rsyslog之前，上面的代码可以像您想象的那样工作。此时，syslog中不再出现任何消息，尽管一切似乎都在正常工作。

Answer 1

与此类似的黑客应该会有所帮助：

    SyslogIF log = new UnixSocketSyslog() {
        @Override
        protected void write(int level, byte[] message) throws SyslogRuntimeException {
            if (this.fd == -1)
                connect();
            if (this.fd == -1)
                return;
            ByteBuffer byteBuffer = ByteBuffer.wrap(message);
            int ret = this.libraryInstance.write(this.fd,byteBuffer,message.length);
            if (ret < 0) {
                shutdown();
                connect();
                if (this.fd == -1)
                    return;
                ret = this.libraryInstance.write(this.fd,byteBuffer,message.length);
            }
        }
    };