在之后的 JFR 事件学习以及调试的过程中，我们会经常用到 WhiteBox API 来触发 JVM 的一些机制或者临界点。例如强制 JVM 现在立刻进行 FullGC 等等。
WhiteBox API 是 HotSpot VM 自带的白盒测试工具，将内部的很多核心机制的 API 暴露出来，用于白盒测试 JVM，压测 JVM 特性，以及辅助学习理解 JVM 并调优参数。WhiteBox API 是 Java 7 引入的，目前 Java 8 LTS 以及 Java 11 LTS（其实是 Java 9+ 以后的所有版本，这里只关心 LTS 版本，Java 9 引入了模块化所以 WhiteBox API 有所变化）都是有的。但是默认这个 API 并没有编译在 JDK 之中，但是他的实现是编译在了 JDK 里面了。所以如果想用这个 API，需要用户自己编译需要的 API，并加入 Java 的 BootClassPath 并启用 WhiteBox API。
换了kali2020之后就没怎么用过BurpSuite贪玩，直到最近做靶机需要爆破，但是社区版只能跑单线程，当我这八核十六线程的主机不要面子的吗？于是找出了大佬们施舍的BurpPor共（po）享（jie）版，但是发现在新版kali里用不了。
记录一下 complete 各个参数含义。 -c 要补全的命令 -p 命令路径 -e -s 短参数 -h -l 长参数 --help -o old style long option -a 添加子命令 -f 不列出文件 -r -x -f and -r -w -n 函数 -CSTRING -C -A -u -d 描述 complete -- edit command specific tab-completions Synopsis complete ( -c | --command |
参数总结 [root@node1 bin]# /export/server/flink/bin/flink --help ./flink <ACTION> [OPTIONS] [ARGUMENTS] The following actions are available: Action "run" compiles and runs a program. Syntax: run [OPTIONS] <jar-file> <arguments> "run" action opti
value (bool) Preselect the checkbox when it first renders. This will be cast to bool internally. key (str or int) An optional string or integer to use as the unique key for the widget. If this is omitted, a key will be generated for the widget based on its content. Multiple widgets of the same type may not share the same key. help (str) An optional tooltip that gets displayed next to the checkbox. on_change (callable) An optional callback invoked when this checkbox's value changes. args (tuple) An optional tuple of args to pass to the callback. kwargs (dict) An optional dict of kwargs to pass to the callback. disabled (bool) An optional boolean, which disables the checkbox if set to True. The default is False. label_visibility ("visible", "hidden", or "collapsed") The visibility of the label. If "hidden", the label doesn't show but there is still empty space for it (equivalent to label=""). If "collapsed", both the label and the space are removed. Default is "visible".
You-Get is a tiny command-line utility to download media contents (videos, audios, images) from the Web, in case there is no other handy way to do it.
在SOA的世界中，最重要的一个概念就是契约（contract）。在云计算的世界中，有关通信的最重要的概念也是契约。XML具有强大对数据的描述能力，Atom格式和AtomPub都建立在XML之上，在Google和微软的推动下，也已经成为标准。但是，Atom/AtomPub和ODBC/OLEDB这样的真正数据交互协议相比较，还有着根本上的欠缺：缺乏数据类型的具体描述，降低了交互性能。缺乏对数据查询的控制能力，比如返回特定的数据集合的区间，或者说分页能力等等。微软基于EDM模型释出了：OData，这里也可以看出E
需要注意的是，服务器端如果是 nc -l 127.0.0.1 1234 就只能本地连接了，所以我们一般都是直接 nc -l 1234
nvm是可以切换管理nodejs版本的开源工具，其中可以看看Github上的仓库。访问nvm的github，根据介绍可以看到相关的安装脚本，如下：
Over the last few years, Google has introduced several new classes to Android for scheduling work that needs to run outside the scope of an application’s lifecycle. Many of these new schedulers implement features that improve battery life, as do updates to older methods. And as of Android Marshmallow, these schedulers became even more efficient thanks to Doze Mode, which doesn’t even require any effort from developers!
NAND is a non-volatile flash memory which can hold data even when it’s not connected to a power source. The ability to retain data when the power is turned off makes NAND a great option for internal, external and portable devices. USB drives, SSDs and SD cards all utilise flash technology, providing memory for devices such as your mobile phone or digital camera.
最近配置一个GridFTP 用于测试其传输FTP性能, 在这里简单记录，备忘；使用本教程可以简单起一个GridFTP用于测试服务；
FindBugs looks for bugs in Java programs. It is based on the concept of bug patterns. A bug pattern is a code idiom that is often an error. Bug patterns arise for a variety of reasons:
在apache的日志里经常看到这个错误: [Fri Oct 08 14:49:18 2004] [error] an unknown filter was not added: php [Fri Oct 08 14:49:18 2004] [error] an unknown filter was not added: php [Fri Oct 08 14:49:20 2004] [error] an unknown filter was not added: php [Fri Oct 08 14:49:20 2004] [error] an unknown filter was not added: php [Fri Oct 08 14:49:40 2004] [error] an unknown filter was not added: php 自己的apache的版本是: [root@eygle logs]# apachectl -v Server version: Apache/2.0.49 Server built: Jun 15 2004 16:55:22 还是自己的经验不够，刚才查了一下，找到了答案:
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4) 移除 Call-time pass by reference（如 call_user_func_array('function', array(&$a) 不支持)
perl 和 Python 在做反弹shell基本差不多，Python 那一节有点讲的太多了，大家可以对比一下参数，照着Python的思路移到 perl 上，我不太懂 perl ，这里就直接上反弹shell的命令了
Note: We have created a brand-new standalone guide for server-side rendering in Vue, it's a recommended read for all users. Also, the HackerNews demo has been updated to reflect the latest best practices.
用OpenSSH的人都知ssh会把你每个你访问过计算机的公钥(public key)都记录在~/.ssh/known_hosts。当下次访问相同计算机时，OpenSSH会核对公钥。如果公钥不同，OpenSSH会发出警告，避免你受到DNS Hijack之类的攻击。
In the previous article, we’ve initialized the ImageLoader with configuration; and now, it is ready for immediate use according to its intended purpose. 在之前的章节，我们已经通过配置初始化了ImageLoader，现在，我们来介绍一下怎么使用ImageLoader For this, it has four overloaded methods:
系统都是ubuntu20.04、22.04，预装的ROS1、ROS2，批量维护升级到最新版本后，遇到如下现象：
This document is a starting point for users working with Hadoop Distributed File System (HDFS) either as a part of a Hadoop cluster or as a stand-alone general purpose distributed file system. While HDFS is designed to "just work" in many environments, a
解决方法见官网：https://datatables.net/manual/tech-notes/4
我们正带领大家开始阅读英文的《CUDA C Programming Guide》,今天是第三天，我们将用三天时间来学习CUDA 的编程接口。希望在接下来的97天里，您可以学习到原汁原味的CUDA，同时能养成英文阅读的习惯。 本文共计1533字，阅读时间30分钟 3. Programming Interface CUDA C provides a simple path for users familiar with the C programming language to easily write
Changes the menu style of menu to menustyle. You may specify more than one menu in each call of ChangeMenuStyle.
这些参数是用于操作和管理Apache Kafka主题的命令行工具参数，通常用于kafka-topics.sh工具。以下是每个参数的描述：
在执行某个程序的时候，我们通常使用命令行參数来进行配置其行为。 命令行选项和參数控制 UNIX 程序，告知它们怎样动作。
发布者：全栈程序员栈长，转载请注明出处：https://javaforall.cn/172200.html原文链接：https://javaforall.cn
项目要求支持 8K 高清视频（H265编码）播放，拿到板子后却发现使用 App 可以播放 8K 高清视频，但使用浏览器却不行，即使安装上最新的 Chrome for Android 也不行。根据以往的浏览器内核开发经验，在 Android 平台上，Chromium WebView 最终是调用系统框架层的 MediaPlayer 进行播放。理论上只要系统框架层能够支持 8K 高清播放，那么浏览器应该也支持。实际情况却并非如此，而且 Android 10 预编译 WebView 没任何日志输出，所以需要下载源码编译 Chromium WebView，找出问题所在。
发布者：全栈程序员栈长，转载请注明出处：https://javaforall.cn/135846.html原文链接：https://javaforall.cn
Feren OS现在是围绕UbuntuLinux18.04和KDE Plasma桌面而不是LinuxMint构建的。肉桂桌面版可能在今年晚些时候退役。
DESCRIPTION This module provides socket operations and some related functions. On Unix, it supports IP (Internet Protocol) and Unix domain sockets. On other systems, it only supports IP. Functions specific for a socket are available as meth
tcpdump: any: You don't have permission to capture on that device
rsync - faster, flexible replacement for rcp
我们使用 go help buildmode 可以看到 go 可以以多种方式进行构建，默认使用静态链接库.
The decision of whether to use multiple simple queries or a join depends on the specific requirements of the query.
https://thomassileo.name/blog/2012/08/20/how-to-keep-celery-running-with-supervisor/
转自：https://docs.elementscompiler.com/Platforms/Cocoa/CpuArchitectures/
在运维系统中，如果需要异步执行一些调度任务的时候，最常用的异步任务队列工具就是celery。但是celery默认是不自带后台运行等功能的，那么怎么办呢？
randrepeat=boolForrandomIOworkloads,seedthegeneratorinapredictablewaysothatresultsarerepeatableacrossrepetitions.Defaultstotrue.randseed=intSeedtherandomnumbergeneratorsbasedonthisseedvalue,tobeabletocontrolwhatsequenceofoutputisbeinggenerated.Ifnotset,therandomsequencedependsontherandrepeatsetting.fallocate=strWhetherpre-allocationisperformedwhenlayingdownfiles.Acceptedvaluesare:noneDonotpre-allocatespaceposixPre-allocateviaposix_fallocate()keepPre-allocateviafallocate()withFALLOC_FL_KEEP_SIZEset0Backward-compatiblealiasfor'none'1Backward-compatiblealiasfor'posix'Maynotbeavailableonallsupportedplatforms.'keep'isonlyavailableonLinux.IfusingZFSonSolaristhismustbesetto'none'becauseZFSdoesn't support it. Default: 'posix'. fadvise_hint=bool By default, fio will use fadvise() to advise the kernel on what IO patterns it is likely to issue. Sometimes you want to test specific IO patterns without telling the kernel about it, in which case you can disable this option. If set, fio will use POSIX_FADV_SEQUENTIAL for sequential IO and POSIX_FADV_RANDOM for random IO. fadvise_stream=int Notify the kernel what write stream ID to place these writes under. Only supported on Linux. Note, this option may change going forward. size=int The total size of file io for this job. Fio will run until this many bytes has been transferred, unless runtime is limited by other options (such as 'runtime', for instance, or increased/decreased by 'io_size'). Unless specific nrfiles and filesize options are given, fio will divide this size between the available files specified by the job. If not set, fio will use the full size of the given files or devices. If the files do not exist, size must be given. It is also possible to give size as a percentage between 1 and 100. If size=20% is given, fio will use 20% of the full size of the given files or devices. io_size=int io_limit=int Normally fio operates within the region set by 'size', which means that the 'size' option sets both the region and size of IO to
hwspinlock 提供一种硬件同步机制，lock 操作可以防止多处理器同时处理共享数据。保证数据的一致性。
试用了几天linq,感觉确实方便，而且生成的sql也还不错,下面是几点体会 1.几种常见的等效select写法 var s = from c in ctx.T_Users select new { c.F_Name, c.F_Sex, c.F_Birthday, c.F_ID } 这种写法对于初学者来说，最容易理解 var s = ctx.T_Users.Select(p => new { p.F_Name, p.F_Sex, p.F_Birthday, p.F_ID }) 这种写法利用T_User
Oracle RAC 安装完毕后的健壮性是一个令人头疼的问题。之前Oracle为之专门推出了raccheck工具，确实方便了我们这些个苦逼的DBA。现在Oracle在raccheck的基础之上又推出了orachk. orachk包含了EXAchk 的功能并替换了流行的 RACcheck 工具，扩大根据用户报告的最重要问题的优先次序的覆盖面，并且主动扫描E-Business Suite Financials Accounts Payables、Oracle Database、Sun Systems等产品的已知问题。下面将为您揭开其面纱。
MySQL的主从搭建大家有很多种方式，传统的mysqldump方式是很多人的选择之一。但对于较大的数据库则该方式并非理想的选择。使用Xtrabackup可以快速轻松的构建或修复mysql主从架构。本文描述了基于现有的从库来快速搭建主从，即作为原主库的一个新从库。该方式的好处是对主库无需备份期间导致的相关性能压力。搭建过程中使用了快速流备份方式来加速主从构建以及描述了加速流式备份的几个参数，供大家参考。
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