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haha.
this rules.
i'll have to read it more thoroughly later. =)
-tcl.
On Tue, 18 Jul 2000, Joseph Mack wrote:
>
> 1st LVS Trivia Quiz, Jul 2000
> To coincide with Wensong's talk at the Ottawa Linux Symposium 19-22 Jul 2000.
>
> (Originally this was prepared for an LVS get together at Ottawa.
> Only Wesong, Lars, Ratz and myself are going, so I'm posting
> this to the mailing list while I'm away.
> Wed Jul 18: we still haven't heard if Wensong got his
> visa in Beijing to go. Good luck Wensong - Joe)
>
> Disclaimer: All questions have been painstakingly researched.
> The answers have not and will be posted after I return from Ottawa.
> (some answers are in the "it depends" category. All correct answers
> are acceptable). Alternate answers and flames from sore losers will
> be hotly disputed on the mailing list after the official answers are posted.
>
> Questions apply to the state of the LVS art at the end of Jun 2000.
>
> Rules: Mark all answers that are correct
> Score: 1 point for every correct answer or factoid.
>
> Competition Divisions:
>
> You can do this
>
> 1. from memory only
>
> 2. using any means at your disposal.
> People using external information are required to drink 1 free beer
> for every piece of help, before going to the next question.
>
> Warning: This quiz may contain references to violence, sex, incitement
> to illegally overthrow the goverment, foul language and bad grammar.
> Then on the other hand it may not. You have been warned.
>
> Personalities Category
>
> 1. Wensong lives in Changsha, China where he's
>
> a. an academic at the National Laboratory for Parallel &
> Distributed Processing
> b. a student
> c. unemployable
>
>
> 2. Who is "hidden"?
>
>
> 3. According to an unofficial count of the postings to the mailing list,
> the most prolific posters are all born in the one country.
>
> a. What's the country
> b. Who are these blabbermouths?
>
> 4. What is Horms real name?
>
>
> 5 The machine that hosts the LVS primary website (www.linuxvirtualserver.org)
> and mailing list
>
> a. is in what country?
> b. is provided by which LVS person?
>
> Total World Domination Category
>
> 1. Name commercial products based on LVS code.
>
>
> Heroics Category
>
> 1 point for each of the following
>
> 1. Set up a working LVS by any method.
>
> 2. Set up a working LVS completely from the command line.
>
> 3. Posted to the mailing list (1 point each)
>
> a. anything at all
> b. something useful
> c. nothing because there is too much noise there already.
>
> 4. Have earned money for LVS work.
>
> Lifestyle Questions
>
> 1. Have you ever programmed through to sunrise, because you couldn't
> stop?
>
> 2. What is the normal number of ball point pens (biros (R)) that you
> can put into a plastic pocket protector in a standard business shirt,
> if you take your calculator out?
>
> 3. What are the advantages of no-iron shirts?
>
> 4. How many females have posted to the mailing list?
>
> a. 0
> b. 1-100
> c. many
>
> Techical Questions
>
> 1. How many penguins are in the LVS logo?
>
> 2. LVS has 3 distinct methods of getting a packet from the director
> to the realservers, VS-NAT, VS-DR, VS-TUN.
>
> a. which put the most load on the director
> b. which have the lowest latency
>
> 3. Which of these pieces of hardware/software/companies are/make an L4 switch
>
> a. F5
> b. cisco
> c. mon
> d. BIG/ip
> e. Matterhorn
> f. Alteon
> g. Redwood
> h. Kudzu
> i. lvs
> j. SGI
> k. ldirectord
>
> 4. Does LVS work on non-Intel Linux directors (if yes, which hardware is
> known to work)
>
> a. yes
> b. no
>
> 5. Does LVS look inside the ethernet frames (or equivalent for other
> transport)
> or does it look at the contents (data) of the packet before deciding
> what to do with it.
>
> a. ethernet frame
> b. data
>
> 6. Can a VS-DR LVS use realservers running
>
> a. NT
> b. other non-linux unices
>
>
> 7. Does the "arp problem" affect
>
> a. VS-NAT
> b. VS-DR
> c. VS-TUN
>
> 8. Under Linux, hidden interfaces may be established that will not
> be advertised via ARP, whether directly connected or otherwise.
> One method of avoiding the ARP problem with VS-DR and VS-TUN is
> to make the interface with the VIP on which host(s) hidden:
>
> a. the director
> b. the realservers
> c. all machines in the LVS
>
> 9. What can you do to handle the "arp problem" on an LVS running
> 2.2.x kernels (1 point for each method).
>
>
> 10. A VS-DR LVS with identical realservers and unweighted round robin
> scheduling for the service telnet, is setup with the VIP on ethernet
> devices. _All_ devices with the VIP reply to arp requests.
> You connect to the LVS'ed service telnet many times in succession from
> a client connected directly to the director and you observe which realserver
> you connect to.
>
> Which of these are possible:
>
> a. you will connect to each realserver in the order listed by ipvsadm
> (ie the LVS works perfectly)
> b. you will connect to each realserver in random order
> c. you will connect to a subset of the realservers in random order
> d. you will always connect to the same realserver
> e. the telnet connect request will hang.
>
> 11. A VS-DR LVS can be made to operate if the VIP is on
>
> a. both the director and the realservers
> b. the director only
> c. the realservers only
> d. none of the machines
>
> 12. You set up a demonstration LVS using some generic Linux boxes on hand.
> The LVS handles telnet using round robin scheduling on 2 realservers,
> but when you attempt to connect, you get "connection refused".
> What could be wrong?
>
> 13. You fix this problem and next time the connection attempt hangs (forever).
> What is likely wrong if the LVS is
>
> a. VS-NAT
> b. VS-DR
>
> 14. You fix this problem and and instead of connecting immediately,
> the connection hangs for a while and then connects. On checking you
> find that connecting to the realserver directly completes immediately.
> What's wrong?
>
> 15. Your pointy haired boss is beginning to think you are crazy and wants to
> buy the TurboLinux Cluster Server, but you doggedly start again and setup
> a VS-DR LVS from scratch.
>
> You get a gratifying immediate connection to one of the realservers. However
> after a few minutes, you realise that you're connecting to the same
> realserver
> every time, rather than alternating between the two realservers. What is
> wrong?
>
> 16. In failover setups where another director can replace a failed director,
> during failover, the connection between the client and realserver is
>
> a. maintained
> b. dropped
> c. hangs
>
>
> 17. What will the client in the previous question see on director failover
> if the connection is
>
> a. idle telnet
> b. active ftp doing a file transfer
> c. idle http, the browser reloads just after the failover completes.
> d. http and is downloading a page at the time the director fails.
>
>
> 18. VS-DR has a different path for packets coming from the client and for
> those returning. The result of this is that services like ftp, which have
> large reply packets and small request packets, have
>
> a. higher maximum throughput
> b. the same maximum thoughtput
> c. lower maximum througput
>
> at the director than services like lpd, which have large request packets
> and small replies.
>
>
> 19. An LVS can recognise/use the fwmark (firewall mark) on a packet.
> The fwmark is put on the packet by the
>
> a. client
> b. routers on the internet
> c. router/firewall just outside the director
> d. director
> e. realserver
>
> 20. The fwmark is recognised/used by the
>
> a. client
> b. routers on the internet
> c. router/firewall just outside the director
> d. director
> e. realserver
>
> 21. The fwmark allows
>
> a. the director not to have a VIP
> b. the director to accept LVS requests destined for a
> subnet of addresses
> c. security precautions to block DoS attacks
>
> 22. A VS-DR realserver is doing an ftp transfer with a client which goes
> down during the transfer. A router near the client sends back a
> "host unreachable" icmp packet.
>
> a. What LVS machine handles this packet?
> b. What does this machine do with the icmp packet
> (eg accept, drop, reject)?
> c. What is the LVS's response to the icmp packet?
>
> (C) Joseph Mack and the LinuxVirtualServer Project 2000.
> May be used anywhere with acknowlegement.
> ---------------------------------------------------------------------------
> Joseph Mack mack@xxxxxxxxxxx
>
>
>
>
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