eth区块同步出现这样的WARN: WARN [06-17|13:02:42] System clock seems off by -51.509894715s, which can prevent network connectivityWARN [06-17|13:02:42] Please enable network time synchronisation in system settings. 处理方案:设置系统同步时间, 对于Linux,可执行: timedatectl set-n…

https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/HdfsDesign.html Introduction [相对于POSIX,放宽要求] The Hadoop Distributed File System (HDFS) is a distributed file system designed to run on commodity hardware. It has many similarities…

Symptom System log (transaction SM21) shows network disconnections, e.g.: Q04 Connection to user 2642 (EXTRACAO), terminal 38 (iguacucp125) lost Delete session 001 after error 061 Operating system call recv failed (error no. 10054) Environment SAP Ap…

在我的Dell Latitude 3330上, 新装的Ubuntu 14.04一切正常,就是没有system settings程序, 以下的命令能够解决: sudo apt-get install ubuntu-desktop 不用重新启动,立马生效.…

win7系统安装了了AndroidStudio3.5后用模拟器报错:Enable VT-x in your BIOS security settings, ensure that HAXM is installed properly. Try disabling 3rd party security software if the problem still occurs. 确定了自己已经打开VT,也已经安装HAMX7.5.4,各种疯狂百度,都说是VT没开或者是HAMX没安装上,百思不得其解.…

1.mac地址不对 通过ip addr查看mac地址,然后修改cd /etc/sysconfig/network-scripts/目录下的文件里面的mac地址 2.通过以下方法 systemctl stop NetworkManager systemctl disable NetworkManager 重新启动网络: systemctl start network.service…

背景 以太坊技术搭建的区块链网络,节点间需要保证时间一致,才能正常有序的发送交易和生成区块,使得众多节点共同维护分布式账本(区块数据+状态数据).但是,网络中节点的系统时间不一致回出现什么现象呢,我们通过2个例子来分析一下. 问题现象: 1. 以太坊节点启动时,报出时间未同步的警告日志: WARN [03-20|17:20:54] System clock seems off by -1m7.049442998s, which can prevent network connectivity W…

Bluetooth —— 蓝牙 The Android platform includes support for the Bluetooth network stack, which allows a device to wirelessly exchange data with other Bluetooth devices. The application framework provides access to the Bluetooth functionality through th…

Bluetooth Using the Bluetooth APIs, an Android application can perform the following: 使用蓝牙APIs,一个Android应用能够进行例如以下操作: Scan for other Bluetooth devices 扫描其它蓝牙设备 Query the local Bluetooth adapter for paired Bluetooth devices 查找本地已经配对的蓝牙设备 Establish RFC…

Lab 8 Manage Network Settings Goal: To build skills needed to manually configure networking Estimated Duration: 45 minutes System Setup: A Red Hat Enterprise Linux System using DHCP networking Lab Setup: Disable the DHCP service on server1. Sequence…