checksum algorithm

This series of articles I saw in the sqlskill.com's PAUL blog, many misunderstandings are more typical and representative, the original from the T-SQL Tuesday #11: Misconceptions about... EVERYTHING !!, After translation and arrangement by our team, it is published on AgileSharp. Hope to help you. Misunderstanding #27: Using BACKUP... with checksum can replace DBCC CheckDB Error At first glance, because backup with

A Download and install Toolshttp://www.percona.com/downloads/percona-toolkit/Currently the latest version is percona-toolkit_2.2.12.tar.gzAfter uploading to the server, unzip and set to environment variablesAdd path to MySQL user's environment variable fileVI. bash_profileExport path= $PATH:/mysqldata/soft/percona-toolkit-2.2.12/bin Two. Use the Pt-table-checksum command to find inconsistent data The primary concern is diffs, 0 is consistent, 1 is in

Datanode verifies the data checksum before actually storing the data. The client writes data to datanode through pipeline. The last datanode checks the checksum. When the client reads data from datanode, it also checks and compares the checksum of the actual data and the checksum on the datanode of the contract.

Misunderstanding #27: Using BACKUP... with checksum can replace DBCC CheckDB Error At first glance, because backup with checksum will detect the CHECKSUM values of all allocated pages, this misunderstanding seems to be the case, but in fact it is not the case, for the following reasons: The page checksums feature of the database upgraded from SQL Server 2000 o

Myth #27: Use Backup ... With checksum can replace DBCC CheckDB Error At first glance, because backup with checksum detects the value of the checksum for all assigned pages, this myth seems to be the case, but it's not really the case, for the following reasons: The database page checksums that was raised by SQL Server 2000 or earlier must be turned on. After it

http://www.iteye.com/topic/1127319The day before yesterday the first blog to the forum, about the Java file Monitoring article, post address in: http://www.iteye.com/topic/1127281Comment on a lot of friends, download code of Friends very much, thank the forum to see my post friends, as well as reply to the comments of friends, to provide me with suggestions of friends.From these suggestions, although the language is short, but there are some words, here to say a bit about the post code in Hashfi

In fact, for a small DBA, sometimes these problems cannot be avoided. Therefore, we need a tool to check whether the master-slave replication is normal and whether an error has occurred. In fact, for a small DBA, sometimes these problems cannot be avoided. Therefore, we need a tool to check whether the master-slave replication is normal and whether an error has occurred. In fact, for a small DBA, sometimes these problems cannot be avoided. Therefore, we need a tool to check whether the mast

Datanode verifies the data checksum before actually storing the data. The client writes data to datanode through pipeline. The last datanode checks the checksum. When the client reads data from datanode, it also checks and compares the checksum of the actual data and the checksum on the datanode of the contract. Ea

DPDK rte_mbuf enable NIC Offload Compute checksum configuration method Compute IP Checksum Mb->l2_len = Len (out_eth) Mb->l3_len = Len (out_ip) mb->ol_flags |= Pkt_tx_ipv4 | Pkt_tx_ip_csum Note:Out_ip.checksum = 0The NIC supports the Dev_tx_offload_ipv4_cksum feature. Compute IP UDP checksum Mb->l2_len = Len (out_eth) Mb->l3_len = Len (out_ip) mb->ol_flags |=

DPDK rte_mbuf enable NIC Offload Compute checksum configuration method Compute IP Checksum Mb->l2_len = Len (out_eth) Mb->l3_len = Len (out_ip) mb->ol_flags |= Pkt_tx_ipv4 | Pkt_tx_ip_csum Note:Out_ip.checksum = 0The NIC supports dev_tx_offload_ipv4_cksum features. Compute IP UDP checksum Mb->l2_len = Len (out_eth) Mb->l3_len = Len (out_ip) mb->ol_flags |= Pk

We know the checksum problem of Linux NAT optimization. Linux NAT is a stateful NAT Based on ip_conntrack, and its configuration is similar to the effect of BSD's keep state! If you take a look at the PREROUTING of Netfilter, you will know that ip_conntrack depends on ip_defrag, that is, all the IP slices of the shard must be reorganized before they can enter ip_conntrack and then enter NAT, if we want to implement NAT for each IP segment, we need to

Struts2 input checksum is divided into two main typesCode implementation checksum XML configuration file implementation checksum(1) Code implementation Verification1, the action all methods to validatethe action needs to inherit Actionsupport, and the action overrides the Validate () method,In the Validate method, the correlation check is based on the correspondi

often use some tools provided by percona-toolkit. By the way, I will simply record them. 1. About pt-table-checksum and pt-table-sync? Pt-table-checksum and pt-table-sync are some useful performance diagnostic tools provided by percona for mysql DBAs. In addition, XtraBackup is often used for backup, this physical backup tool is used to provide hot backup for innodb of mysql and warm backup for myisam. Pt

How to find the checksum of UDP, my IP is the 192.168.1.59 port number is 30002 The connected machine is the 192.168.1.179 port number is 30000 And then how do you find the checksum? Reply to discussion (solution) Goo ~ (???) B Don't understand is chechsum how to get to, also have byte length? Do I need a byte length? Byte length If it is 66 then how to get to this

Web|web Standard | Mistakes have been hard for many days and we've worked hard to learn to use XHTML+CSS to redesign our site. So how do we know that our own pages really conform to the Web standards? The Web site and some volunteer websites provide online calibration programs to help us check whether the page meets the standards and provide help for correcting errors. These checksums are very useful and are the first thing I want to do when I debug the page. 1.XHTML

MySQL Q A talked about whether checksum table can be used to verify data consistency before and after the logical backup. Some interesting problems are found, such as different data insertion sequence, different table engines, and different operating system bits. Whether the insert order of www.2cto.com varies. We know that the full table scan can have many orders. Especially when the delete action appears in the table, the logical export operation i

I. There are a large number of view pages in a Web system project that require users to enter a lot of data themselves. There are many types of these data. In order to prevent some customers from malicious input and malicious damage to Web projects, you must introduce input validation, like the Windows operating system firewall to filter out some of the junk data, blocking outside the web system. Next, let's introduce the Validate input check method:1.validate method for input verification: here

Details about TCP and UDP pseudo Headers Recently, I was reading the TCP/IP explanation of the Steven S, which introduced the UDP and TCP pseudo headers but not detailed enough. It only exists for the UDP and TCP Checksum, at the same time, a pseudo-header diagram is provided, which is directly added to the front of the UDP header. The Confusion seems to be real. In fact, this diagram should be represented by a dotted line, the following des

Pt-table-checksum Use Practice The most contact in the work is the MySQL replication, because now the company is also using the MySQL 5.1.x version, in the replication is still a lot of problems, such as the main library down or from the library downtime will cause replication interruption, usually we need to do artificial repair (MySQL The 5.5 version solves most of the problems), or a lot of times it is necessary to promote a master library from th

We use XHTML+CSS to redesign our site, how do we know that our own pages really conform to Web standards? The Web site and some volunteer websites provide online calibration programs to help us check whether the page meets the standards and provide help for correcting errors. These checksums are very useful and are the first thing I want to do when I debug the page. 1.XHTML Checksum Verification URL: http://validator.w3.org/ Check mode: URL check, fil