First to help people join the discussion, the guilty paragraph of certification study guide 42.1 -------------------------------------------------------------------------------------------------------------- Each server must have its own network interfaces, including the TCP/IP port, the named pipe or shared memory (on Windows), and the Unix socket file (on Unix). One server cannot use network interfaces that are used by another server; it will not even start up properly if it discovers that its network interfaces are already in use. Note that it isn't necessary to set up multiple hostnames for the server host. All the MySQL servers running on a given host can share the same hostname. They can also share the same IP address as long as they listen on different TCP/IP port numbers. --------------------------------------------------------------------------------------------------------------
Hey John, I am really interested in this discussions, as you see! I understand perfectly what is the meaning with the MySQL certificator/certified glasses, but I am not really use to see a unit socket file as a network interface, not even the shared memory. I understand that this is all about semantic but I guess there is 99% that rather would call the 'mysql network interface' simply as a communication channel, pipeline, or stack. Named pipes, Shared Memory, Unix socket file have nothing to do with network, they live on the same server, and do not even need any network protocol. [X] Named pipes and Shared Memory are means for windows channel for interprocess communication [X] Unix socket file is same thing on unix systems, using a file as pipe. I am not confusing hardware and software, I do not care if and how many physical cards are in the host, for me the network interface is a layer of software that enable two or more systems to communicate over a network of interconnected systems, be the interconnection medium any, ethernet, wireless, bluetooth, CDN, The network card must be bridging the physical medium that transport information with the host, so it can be any piece of hardware, but the greatness of standards and protocols is abstraction, and thank the Lord! We have the internet accessible from almost everywhere! DSL, WI-FI, UMTS, 3G, also I tried TCP/IP over Bluetooth! I just need from a O.S. level have available a network interface (see virtual hosts, they can all be bound to the same physical card) Would you please issue and comment the following commands? $man ifconfig $ifconfig eth0 I am positive that the book is using the words 'network interface' using a meaning that is only in the mind of the authors, and a few more. Claudio 2009/2/5 John Daisley <john.dais...@mypostoffice.co.uk> > Claudio, > > Nobody is arguing, its a discussion list not an arguing list and this is a > good discussion to have on here. Im very interested in seeing what others > have to say about this but here is how I interpret it (based on my 18 > years of IT experience which includes many years working with MySQL > including becoming mysql dba and dev certified amongst many other > certifications) > > I would say in terms of the MySQL server the interface is either a TCP/IP > Port, a Named Pipe, shared memory or a UNIX Socket. Depending on the host > operating system it can use any of those interfaces but each instance must > have its own interface. > > I believe you are confusing server hardware and server software. Do you > consider a server to be a physical machine or an application that runs on > a physical machine? Its the same difference. The network card is physical > hardware, the port is not! > > John > > > John, > > I don't want to argue too much on this but I'd also like the opinion of > > the > > big heads in MySQL > > > > I think there's no grey area here. > > An interface is an interface and can be of any type and supporting any > > protocol(TCP/IP on ethernet card, UDP idem. DSL on WAN card, PPP on POTS > > modem) > > > > A port is related ONLY to the TCP/IP protocol(in this case) > > > > Moreover, are all the *nix systems wrong? > > > > > --------------------------------------------------------------------------------------------------- > > [c...@terramia ~]$ man ifconfig > > IFCONFIG(8) Linux Programmer's Manual > > IFCONFIG(8) > > > > NAME > > ifconfig - configure a network interface > > > > SYNOPSIS > > ifconfig [interface] > > ifconfig interface [aftype] options | address ... > > > ---------------------------------------------------------------------------------------------------- > > > > So, let's see what a 'network interface' is: > > > ---------------------------------------------------------------------------------------------------- > > [c...@terramia ~]$ /sbin/ifconfig eth0 > > > > eth0 Link encap:Ethernet HWaddr 00:1C:23:3F:CB:C0 > > inet addr:10.xxx.xxx.xxx Bcast:10.xxx.xxx.xxx > > Mask:255.255.255.0 > > inet6 addr: fe80::21c:23ff:fe3f:cbc0/64 Scope:Link > > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > > RX packets:4057947 errors:0 dropped:0 overruns:0 frame:0 > > TX packets:3932495 errors:0 dropped:0 overruns:0 carrier:0 > > collisions:0 txqueuelen:1000 > > RX bytes:851379513 (811.9 MiB) TX bytes:1896970616 (1.7 GiB) > > Interrupt:177 > > > ---------------------------------------------------------------------------------------------------- > > Aren't we supposed to see just a port number here? > > > > Cheers > > Claudio > > > > > > 2009/2/5 John Daisley <john.dais...@mypostoffice.co.uk> > > > >> An interface by definition is a point of interconnection. > >> > >> Maybe its a bit of a grey area where the interpretation can be different > >> depending on whether you think in terms of hardware or software. > >> > >> Its the port which is used to communicate with the MySQL (or indeed any > >> other) server software so therefore for the server software (but maybe > >> not > >> the physical hardware) its the port which is the point of > >> interconnection > >> (the network interface). > >> > >> For me the book is correct but I can see where confusion could occur. > >> > >> John > >> > >> > Hi Claudio, > >> > > >> > I don't think its your English, I agree with you that its not just > >> > confusing it is wrong. > >> > > >> > "Each server must have its own network interface" > >> > > >> > At least for my 10 years experience in IT and UNIX I would understand > >> > network interface as physical network interface unless specified as > >> > otherwise. Maybe the MySQL community has a differenet opinion :P > >> > > >> > > >> > > >> > ;) > >> > > >> > cheers Andy. > >> > > >> > ---------------------------------------------------------------- > >> > This message was sent using IMP, the Internet Messaging Program. > >> > > >> > > >> > -- > >> > MySQL General Mailing List > >> > For list archives: http://lists.mysql.com/mysql > >> > To unsubscribe: > >> > > http://lists.mysql.com/mysql?unsub=john.dais...@butterflysystems.co.uk > >> > > >> > > >> > ______________________________________________ > >> > This email has been scanned by Netintelligence > >> > http://www.netintelligence.com/email > >> > > >> > > >> > >> > >> > > > > > > ______________________________________________ > > This email has been scanned by Netintelligence > > http://www.netintelligence.com/email > > > > >
