NiFi引导程序如何确定NiFi是否未运行？

Question

我看到NiFi偶尔会被重启。在nifi-app.log中，没有错误的指示。NiFi没有处理任何数据，服务器此时不忙。当我在nifi-bootstrap.log中看到时，我看到

2021-06-17 16:44:00,551 DEBUG  [main] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.status
2021-06-17 16:44:00,551 DEBUG  [main] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.lock
2021-06-17 16:44:00,551 WARN  [main] org.apache.nifi.bootstrap.RunNiFi Apache NiFi appears to have died. Restarting...
2021-06-17 16:44:00,552 DEBUG  [main] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.pid
2021-06-17 16:44:00,555 DEBUG  [main] org.apache.nifi.bootstrap.RunNiFi Saved Pid 17260 to /opt/nifi-1.10.0/run/nifi.pid
2021-06-17 16:44:00,555 DEBUG  [main] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.status
2021-06-17 16:44:00,557 DEBUG  [main] org.apache.nifi.bootstrap.RunNiFi Saved Properties {pid=17260} to /opt/nifi-1.10.0/run/nifi.status
2021-06-17 16:44:00,557 INFO  [main] org.apache.nifi.bootstrap.Command Launched Apache NiFi with Process ID 17260
2021-06-17 16:44:00,558 INFO  [main] org.apache.nifi.bootstrap.RunNiFi Successfully started Apache NiFi with PID 17260
2021-06-17 16:44:01,128 DEBUG  [NiFi Bootstrap Command Listener] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.status
2021-06-17 16:44:01,128 DEBUG  [NiFi Bootstrap Command Listener] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.pid
2021-06-17 16:44:01,131 DEBUG  [NiFi Bootstrap Command Listener] org.apache.nifi.bootstrap.RunNiFi Saved Pid 17260 to /opt/nifi-1.10.0/run/nifi.pid
2021-06-17 16:44:01,131 DEBUG  [NiFi Bootstrap Command Listener] org.apache.nifi.bootstrap.RunNiFi Status File: /opt/nifi-1.10.0/run/nifi.status

我的问题是:引导过程是如何确定"NiFi似乎已经死亡“的？它是否正在查找nifi.pid和nifi.status文件的存在？如果是这样的话，它多久检查一次？是可配置的吗？

Answer 1

根据源代码nifi-bootstrap，通过检查进程是否有可用的退出代码，每秒(不可配置)检查主进程是否处于活动状态。

https://github.com/apache/nifi/blob/820b2cff29bf3a0d97399667264591b995cc9e45/nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/RunNiFi.java#L1273

            while (true) {
                final boolean alive = isAlive(process);

                if (alive) {
                    try {
                        Thread.sleep(1000L);
                    } catch (final InterruptedException ie) {
                    }
                } else {
                    ... restart process ...

https://github.com/apache/nifi/blob/820b2cff29bf3a0d97399667264591b995cc9e45/nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/RunNiFi.java#L1028

    public static boolean isAlive(final Process process) {
        try {
            process.exitValue();
            return false;
        } catch (final IllegalStateException | IllegalThreadStateException itse) {
            return true;
        }
    }

听起来你的主要nifi进程因为某种原因而停止了…检查服务器上可用的内存和bootstrap.conf中的-Xms和-Xmx参数-通常这是主要原因。