ccna levels

In previous articles, we have discussed several main aspects of URL Rewrite. In the last article of this series, we will discuss some details and features about different levels of URL Rewrite. Theoretically, IIS-level URL Rewrite is written in C or C ++, which is better than ASP. NET-level URL Rewrite written in managed code. However, I think this gap is negligible in most cases. This performance is almost impossible to become a performance bottlene

Relationship between locks and isolation levels One. net project, occasionally some strange problems, recently made up effort to troubleshoot and found that it is caused by a deadlock, the following is a deadlock situation map tracked using SQL Server Profiler: When I see this picture, it is really drunk to tell the truth. It is rare that such a complicated deadlock occurs in a business system that is not complex yet. The cause of this problem is ver

The concept of business intelligence is no longer unfamiliar in the enterprise, but for the implementation of this system, there are still many enterprises feel at a loss, even feel impossible, to the domestic professionals said that the implementation of BI is actually very simple, only need to go through four levels can be very good execution. So, what are the four levels?Level one, meet enterprise busine

Too Many levels of symbolic links questions posted on 2011-11-30 20:33 Zhang He Reading (5826) Comments (0) Edit Collection Today got a zendstudio, placed under the user under a folder, want to execute the program Zendstudio to do a link to/usr/sbin directory. The command is then used:Ln-s./zendstudio/usr/sbinHowever, when the implementation of the Zendstudio prompt "Too many levels of symbolic links" This

ecl circuits typically has relatively small logic spans of approximately of MV. Because of the small span, to-drive TTL circuits from ECL levels normally entails the use of level converters, such as the MC10125, or comparators. Such circuits is relatively power-hungry and expensive. However, they is sometimes simply unnecessary. The circuit infigure 1allows-trigger some TTL circuitry by generating a fairly short negative-going pul Se from the trailing

Professional customization of three levels of distribution, micro-distribution website system development and construction, Professional customization of three levels of distribution, micro-distribution website system development and construction of unlimited level of distribution three levels of profit:Through the mobile social networking platform (Weibo, QQ sp

Four isolation levels for mysql transactions! -- [If! Mso] stylev:* {behavior: url (# default # VML);} o: * {behavior: url (# default # VML);} w: * {behavior: url (# default # VML );}. shape {behavior: url (# default # VML);} style! [Endif] --? Do we know that transactions have four features? (1) Original Four isolation levels for mysql transactions! -- [If! Mso] style v \: * {behavior: url (# default # VML

Today found a PHP write compressed picture program, can be divided into 10 levels (0-9) to compress, 0 grade when the compression ratio is not very large, the picture will not be distorted; As the compression level increases, the picture will become more and more unclear, usually compressed after the image size can be reduced to the original 50%, compression ratio is quite large.The following is a PHP compressed picture programHeader ("Content-type:im

The topic for programmers working with databases is that transactions , as a programming model for an application that simplifies access to a database. By using transactions, applications can ignore some of the potential error scenarios and concurrency problems that the database is responsible for processing. Instead of requiring transactions for every application, sometimes weakening transactional guarantees or completely discarding transactions, you can achieve higher performance or higher ava

reduced the run level to 2, Init will execute the k45named script.The different run levels are defined as follows: (refer to Linux/etc/inittab)# The default run level, the level used by RHS is as follows:# 0-Shut down, machine off.# 1-Single user mode. Just like the safe mode under Win9x.# 2-Multiple users, but no NFS access to multi-user mode without network Service# 3-Full multi-user mode, is the standard run level.# 4-not used, generally not, in s

historical development, regardless of the 2~5 between, there is no difference.Or because of the use of systemd this, so that some previous articles on how to modify the system RunLevel, in 16.04 does not take effect issues. Then to modify the RunLevel, you can refer to this article to modify: https://askubuntu.com/questions/788323/change-runlevel-on-16-04Other findings:If 16.04 of the system has 5 as the default level, then after I set up a service, I put it on the level 2 will not run it? This

, then Servicea.methoda fails to roll back, and Serviceb.methodb is not rolled back. If Serviceb.methodb fails to roll back, if the exception it throws is captured by Servicea.methoda , Servicea.methoda The transaction may still be committed. If ServiceA.methodA the transaction propagation behavior is PROPAGATION_REQUIRED , and ServiceB.methodB The transaction propagation behavior is PROPAGATION_NOT_SUPPORTED , then when the transaction is executed, the transactions are ServiceB.meth

There are 7 runtime run levels under LinuxRun Level 0 system shutdown state, the system default RunLevel cannot be set to 0, otherwise it will not start normallyRun Level 1 single user working status, root privilege, for system maintenance, remote login ForbiddenRun Level 2 multi-user state (no NFS)Run Level 3 full multiuser state (with NFS), enter console command line mode after loginRun Level 4 system not used, reservedRun Level 5 X11 console, enter