pom.xml:
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.1</version>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
<configuration>
<descriptors>
<descriptor>src/main/assembly/descriptor.xml</descriptor>
</descriptors>
<archiverConfig>
<directoryMode>0755</directoryMode>
<defaultDirectoryMode>0755</defaultDirectoryMode>
<fileMode>0644</fileMode>
</archiverConfig>
</configuration>
</plugin>
src/main/assembly/descriptor.xml，在此文件覆盖：
<fileSets>
<fileSet>
<directory>src/conf</directory>
<outputDirectory>conf</outputDirectory>
<fileMode>0600</fileMode>
<directoryMode>0700</directoryMode>
</fileSet>
<fileSet>
<directory>src/db</directory>
<outputDirectory>db</outputDirectory>
</fileSet>
<fileSet>
<directory>src/bin</directory>
<outputDirectory>bin</outputDirectory>
<fileMode>0755</fileMode>
</fileSet>
nohup命令及其输出文件
nohup命令：如果你正在运行一个进程，而且你觉得在退出帐户时该进程还不会结束，那么可以使用nohup命令。该命令可以在你退出帐户/关闭终端之后继续运行相应的进程。nohup就是不挂起的意思( n ohang up)。
一般都是在linux下nohup格式：
nohup command
或者
nohup command &
这之间的差别是带&的命令行，即使terminal（终端）关闭，或者电脑死机程序依然运行（前提是你把程序递交到服务器上）；
它把标准输出（STDOUT）和标准错误（STDERR）结果输出到nohup.txt文件这个看似很方便，但是当输出很大的时候，nohup.txt文件会非常大，或者多个后台命令的时候大家都会输出到nohup.txt文件，不利于查找结果和调试程序。
所以能够重定向输出会非常方便。下面要介绍标准输出，标准输入 和标准错误了。
其实我们一直都在用，只是没有注意到，
比如
>./command.sh > output
#这其中的>就是标准输出符号，其实是 1>output 的缩写
>./command.sh 2> output
＃这里的2>就是将标准错误输出到output文件里。
而0< 则是标准输入了。
下面步入正题，重定向后台命令
>nohup ./command.sh > output 2>&1 &
解释：前面的nohup 和后面的&我想大家都能明白了把。
主要是中间的 2>&1的意思
这个意思是把标准错误（2）重定向到标准输出中（1），而标准输出又导入文件output里面， www.2cto.com
所以结果是标准错误和标准输出都导入文件output里面了。
至于为什么需要将标准错误重定向到标准输出的原因，那就归结为标准错误没有缓冲区，而stdout有。
这就会导致 >output 2>output 文件output被两次打开，而stdout和stderr将会竞争覆盖，这肯定不是我门想要的.
这就是为什么有人会写成：
nohup ./command.sh >output 2>output
出错的原因了
##########################
最后谈一下/dev/null文件的作用
这是一个无底洞，任何东西都可以定向到这里，但是却无法打开。
所以一般很大的stdou和stderr当你不关心的时候可以利用stdout和stderr定向到这里
>./command.sh >/dev/null 2>&1
When we want to do something later in our Java code, we often turn to the ScheduledExecutorService. This class has a method called schedule(), and we can pass it some code to be run later like this:
ScheduledExecutorService executor =
Executors.newScheduledThreadPool(4);
executor.schedule(
() -> {System.out.println("..later");},
1,
TimeUnit.SECONDS
);
System.out.println("do
");
// (Don't forget to shut down the executor later)The above code prints “do…” and then one second later it prints “…later”.
We can even write code that does some work and returns a result in a similar way:
// (Make the executor as above.)
ScheduledFuture future = executor.schedule(
() -> 10 + 25, 1, TimeUnit.SECONDS);
System.out.println("answer=" + future.get())
The above code prints “answer=35”. When we call get() it blocks waiting for the scheduler to run the task and mark the ScheduledFuture as complete, and then returns the answer to the sum (10 + 25) when it is ready.
This is all very well, but you may note that the Future returned from schedule() is a ScheduledFuture, and a ScheduledFuture is not a CompletableFuture.
Why do you care? Well, you might care if you want to do something after the scheduled task is completed. Of course, you can call get(), and block, and then do something, but if you want to react asynchronously without blocking, this won’t work.
The normal way to run some code after a Future has completed is to call one of the “then*” or “when*” methods on the Future, but these methods are only available on CompletableFuture, not ScheduledFuture.
Never fear, we have figured this out for you. We present a small wrapper for schedule that transforms your ScheduledFuture into a CompletableFuture. Here’s how to use it:
CompletableFuture<Integer> future =
ScheduledCompletable.schedule(
executor,
() -> 10 + 25,
1,
TimeUnit.SECONDS
);
future.thenAccept(
answer -> {System.out.println(answer);}
);
System.out.println("Answer coming
")
The above code prints “Answer coming…” and then “35”, so we can see that we don’t block the main thread waiting for the answer to come back.
So far, we have scheduled a synchronous task to run in the background after a delay, and wrapped its result in a CompletableFuture to allow us to chain more tasks after it.
In fact, what we often want to do is schedule a delayed task that is itself asynchronous, and already returns a CompletableFuture. In this case it feels particularly natural to get the result back as a CompletableFuture, but with the current ScheduledExecutorService interface we can’t easily do it.
It’s OK, we’ve figured that out too:
Supplier<CompletableFuture<Integer>> asyncTask = () ->
CompletableFuture.completedFuture(10 + 25);
CompletableFuture<Integer> future =
ScheduledCompletable.scheduleAsync(
executor, asyncTask, 1, TimeUnit.SECONDS);
future.thenAccept(
answer -> {System.out.println(answer);}
);
System.out.println("Answer coming
")
The above code prints “Answer coming…” and then “35”, so we can see that our existing asynchronous task was scheduled in the background, and we didn’t have to block the main thread waiting for it. Also, under the hood, we are not blocking the ScheduledExecutorService‘s thread (from its pool) while the async task is running – that task just runs in whatever thread it was assigned when it was created. (Note: in our example we don’t really run an async task at all, but just immediately return a completed Future, but this does work for real async tasks.)
I know you’re wondering how we achieved all this. First, here’s how we run a simple blocking task in the background and wrap it in a CompletableFuture:
public static <T> CompletableFuture<T> schedule(
ScheduledExecutorService executor,
Supplier<T> command,
long delay,
TimeUnit unit
) {
CompletableFuture<T> completableFuture = new CompletableFuture<>();
executor.schedule(
(() -> {
try {
return completableFuture.complete(command.get());
} catch (Throwable t) {
return completableFuture.completeExceptionally(t);
}
}),
delay,
unit
);
return completableFuture;
}
And here’s how we delay execution of an async task but still return its result in a CompletableFuture:
public static <T> CompletableFuture<T> scheduleAsync(
ScheduledExecutorService executor,
Supplier<CompletableFuture<T>> command,
long delay,
TimeUnit unit
) {
CompletableFuture<T> completableFuture = new CompletableFuture<>();
executor.schedule(
(() -> {
command.get().thenAccept(
t -> {completableFuture.complete(t);}
)
.exceptionally(
t -> {completableFuture.completeExceptionally(t);return null;}
);
}),
delay,
unit
);
return completableFuture;
}
Note that this should all work to run methods like exceptionally(), thenAccept(), whenComplete() etc.
Feedback and improvements welcome!
https://www.artificialworlds.net/blog/2019/04/05/scheduling-a-task-in-java-within-a-completablefuture/
很久以前多线程是这样创建：
Thread t1 = new Thread();
Thread t2 = new Thread();
t1.start(); // 启动新线程
t2.start(); // 启动新线程
由于创建和销毁线程是非常耗资源，因此改成线程建好后不销毁，可以重用，用户只需提供run方法的具体实现：
public static void main(String[] args) throws Exception {
ExecutorService executor = Executors.newSingleThreadExecutor();
Future<String> stringFuture = executor.submit(new Callable<String>() {
@Override
public String call() throws Exception {
Thread.sleep(2000);
return "async thread";
}
});
Thread.sleep(1000);
System.out.println("main thread");
System.out.println(stringFuture.get());
}
但如果很多线程被创建，并且线程间有依赖，即按流程和条件执行线程，实现起来就有点复杂，于是CompletableFuture横空出世。一共有50各方法可供使用。
CompletableFuture.supplyAsync()，相当于创建了ExecutorService，同时也创建了Callable，然后提交到线程池中执行。
CompletableFuture<String> futureA = CompletableFuture.supplyAsync(() -> "任务A");
CompletableFuture<String> futureB = CompletableFuture.supplyAsync(() -> "任务B");
CompletableFuture<String> futureC = futureB.thenApply(b -> {
System.out.println("执行任务C.");
System.out.println("参数:" + b);//参数:任务B
return "a";
});
!!How to use CompletableFuture and Callable in Java
https://ducmanhphan.github.io/2020-02-10-How-to-use-CompletableFuture-Callable-in-Java/使用CompletableFuture优化你的代码执行效率
https://www.cnblogs.com/fingerboy/p/9948736.htmlCompletableFuture 使用详解
https://www.jianshu.com/p/6bac52527ca4使用CompletableFuture
https://www.liaoxuefeng.com/wiki/1252599548343744/1306581182447650https://github.com/eugenp/tutorials/blob/master/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/completablefuture/CompletableFutureLongRunningUnitTest.java
/etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
#symbolic-links=0
#vish start
open_files_limit = 8000
max_connections = 500
#set-variable=max_connections=500
thread_concurrency = 8
#concurrent_insert=2
thread_cache_size=2000
interactive_timeout=180
wait_timeout=180
max_allowed_packet = 32M
key_buffer_size = 3000M
read_buffer_size = 16M
read_rnd_buffer_size = 4M
bulk_insert_buffer_size = 256M
myisam_sort_buffer_size = 16M
myisam_max_sort_file_size = 256M
myisam_repair_threads = 1
#myisam_recover = 4
max_heap_table_size = 2048M
tmp_table_size = 1024M
table_open_cache = 2000
table_cache = 2000
sort_buffer_size = 128M
join_buffer_size = 128M
query_cache_size = 128M
query_cache_limit = 128M
#slow_query_log=1
log-slow-queries
long_query_time=2
#log_queries_not_using_indexes=1
slow_query_log_file = /var/log/mariadb/host_name-slow.log
[mysqldump]
user=root
password=*********
#max_allowed_packet = 1024M
[myisamchk]
key_buffer_size = 2500M
sort_buffer_size = 1024M
read_buffer = 32M
write_buffer = 32M
[innodb]
innodb_buffer_pool_size=3G
innodb_buffer_pool_instance=2
innodb_additional_mem_pool_size=20M
innodb_log_file_size= 512M
innodb_log_buffer_size=16M
innodb_flush_log_at_trx_commit=1
innodb_thread_concurrency=16
#innodb_read_io_threads=16
#innodb_write_io_threads=16
#innodb_io_capacity=2000
#innodb_lock_wait_timeout=120
innodb_flush_method=O_DIRECT
#vish end
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
#!includedir /etc/my.cnf.d