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Siete, Kvalita kódu, objektove metody vyvoje software, Ad-hoc, MANETs,…

- - - - number of hops
      - udp periodic information exchange
      - small networks
      - information exchanged just with neighbors
    - - bandwidth, delay, reliability, load
  - - - information exchanged with all routers
      - cost as metric
      - routing areas
      - load-balancing -- ECMP
      - CIDR
      - ip datagrams
      - richer
    - - link layer frames
      - less chatty
  - - - hop count
      - advertisements
    - - internal IBGP - send traffic from within AS to other AS
      - ibgp peers do not exchange info
  - - - IGP -- RIP, OSPF
    - - EGP -- BGP
  - - - classful
      - cidr
        
        memory usage
        
        scalability
        
        updatability
        
        naive is O(n), Trie is O(m)
    - - providing prefential treatment
      - accounting
      - attack prevention
  - - - just measurment
    - - route demand traffic between two points with respect to cost, delay, bandwidth
      - multi commodity flow
        
        MCSPRF
  - - - Edge
      - Core
    - - Downstream-on-demand
      - Downstream-unsolicited
      - Label distribution protocol (LDP)
    - - Grid-enabled GMPLS
      - packet switch capable
      - time-division multiplexing capable
      - lambda-switch capable
      - fiber-switch capable
  - - - link bandwidth
      - propagation delay
      - Link State Advertisements (LSA)
- - - - delivery
      - acccuracy
      - timeliness
      - ideal network (6)
      - real network (6)
      - efektívnosť
      - fairness
      - decentralised management
      - convergence
      - reliability
      - data flow control
      - connection oriented networks
      - connection-less networks
    - - de facto/de iure
      - quality,security, compatibility,interoperability,portability
    - - physical/fyzicka/copper/rs-232
      - data link layer/datovy spoj/CSMA/ARP
      - network/sitova/IP/ICMP
      - transport/transportna/TCP/UDP
      - session/relacna/netbios/rpc
      - presentation/prezencna/SSL/JPEG
      - Application/aplikacna/HTTP/FTP
  - - - address space exhaustion
      - mobility
      - header simplification
      - real time transfers
      - autoconfiguration
    - - unicast
      - multicast
      - anycast
      - 48 -- global routing prefix -- 2001
        
        16 -- 2001 -- unicast
        
        16 -- RIR
        
        16 -- LIR
      - 64 -- subnet adresa
      - 64 adresa rozhrania
    - - Duplicate address detection DAD
      - Neighbour unreachability detection
      - ICMP
        
        RS
        
        RA
        
        autoconfiguration flags
        
        router lifetime
        
        reachable time
        
        retransmission time
        
        options
        
        source L2
        
        MTU
        
        prefix info
        
        NS
        
        NA
        
        ICMP redirect
    - - well known prefix & poslednych 24 bitov hladanej adresy
      - odpovie len ten koho sa to tyka zo vsetkymi svojimi adresamy
    - - incomplete
      - reachable
      - delay
      - stale
    - - stateful
      - stateless
        
        Link local address generation
        
        Link local addres uniqueness test
        
        Link local address assignment
        
        Router contact (RA/RS)
        
        Router direction
        
        Global address configuration
    - - home address
      - care of address
      - correspondent node
      - home agent
      - bidirectional tuneling vs route optimization
      - return routability (RR) procedure
        
        home test init
        
        care-of test ini
        
        home test
        
        care-of test
    - - CIA
      - AAA
      - encryption, secure checksums
      - IPsec
        
        authentication header (AH)
        
        encapsulating security payload (ESP)
        
        security associations (SA)
        
        key
        
        authentication mechanism
        
        additional parameters
        
        security parameter index (SPI)
        
        IP destination address
        
        security protocol identifier
        
        establish
        
        ISAKMP
        
        IKEv1
        
        IKEv2
        
        sec channel to negotiate
        
        sec channel to transport data
        
        transport mode
        
        tunnel mode
    - - integrated services
      - differentiated services
        
        type of service
        
        traffic class (PRI)
        
        flow label
    - - dual stack
      - tunneling
      - translators
- - - - obmedzenie pouzitia sluzieb
      - signatura su vstupne a vystupne parametry
      - specifikuje kontrakt
  - - - deklarativny jazyk
      - doplna UML
      - nema side effects ako napr ukladanie hodnot
      - specifikacia invariatov, typov, kontraktov, testov
      - constraints - invariant, precondition, postcondition
      - context - spojenie OCL so specifickou triedou/interfacom
      - context Flight inv flightDuration: duration < 4
        context Flight::shiftDeparture (t:Integer) pre: t>0
        context Flight::shiftDeparture (t:Integer):Time post: result = departureTime + t
      - constraints sa dedia
      - kolekcie a operacie s nimi - exist, for all, select
    - - corba idl popisovaci jazyk pre corbu
- - - - DocumentBuilderFactory
      - nezavislost vytvarania instancii
    - - StringBuilder
      - konstrukcia objektu z nezavislych casti
    - - cloning support
      - predrobim si objekty roznych druhov a potom ich klonujem
      - oplati sa extra ked konstrukcny cas > klonovaci cas
    - - jedina instancia objektu pre vsetkych
      - DbConnection
  - - - spaja nesediace interfaces
      - class vs object adapter (inheritance vs composition)
    - - composition
    - - for tree like structures
      - friends with chain of responsibility
    - - add functionality to existing class
      - na rozdiel od adaptera ma enhanced interface
    - - zjednodusene rozhranie komplexneho systemu
      - na rozdiel od mediatora nepridava funkcionalitu a objekty pod nou mozu komunikovat
    - - skoro singleton ale nemame requirement na jedinu instanciu a flyweight musi byt immutable
    - - na rozdiel od adaptera sa nemeni interface
  - - - umoznuje abstraktne prechadzat decka agregatu - schovava realny pristup k polu/setu/db etc
    - - ukladanie snapshotov stavu objektu
      - together with command can implement undo
    - - publish/subscribe
    - - in different states methods have different implementations
      - context object holds reference to current state object with current methods implementation
    - - kind of like state but objects are independent
    - - trieda implementuje operacie pre nejake triedy, ktore implementuju accept. Accept zavola appropriate metodu visitora, napriklad pri iterovani iteratorom
    - - triedy implementuju metody, deleguju vykonavanie metod na ine triedy (mayhaps rekurzivne), CoR sa pouzije na prebublanie metody k spravnej triede
      - midleware v http serveroch
- - - - multi point relays
  - - - Route Request RREQ
      - Route Reply RREP
    - - early RREQ
      - no source routing
- - - - sending in progress
        
        busy tone protocol
        
        split channel into data and control
        
        signal on the control channel
        
        poor bw utilization
      - before sending
        
        Multiple Access Collision Avoidance MACA
        
        Request To Send RTS
        
        Clear To Send CTS
        
        Network Allocation Vector NAV
        
        Power-Control MAC PCM
        
        send RTS/CTS on max power
        
        from this determine minimum required power
        
        Sensor-MAC
        
        switch nodes off, set up schedule when they are listening
        
        can use the same channel
- - - - project charter
        
        why, what, who, how, when
      - manazment klucovych strategii
        
        communication managment strategy
        
        risk management strategy
        
        change management strategy
        
        quality management strategy
        
        product backlog management
    - - ceremonies
      - konflikty
        
        latent/emergent/escalated
  - - - project brief
      - high-level requirements (UP)
      - feasibility analysis (UP)
      - outline architecture (UP)
      - next stage plan
        
        WBS
    - - project initiation documentation
      - detailed requirements (UP)
      - stage report
      - next stage plan
    - - robust architecture (UP)
      - controlling stage
      - managing product delivery
      - managing stage boundary
    - - system acceptance
      - transistion phase
      - product acceptance testing
    - - product handover
      - archivacia
      - end project report
      - lessons learned report
- - - - dopredny prechod
        
        early start ES early finish
      - spatny prechod
        
        late finish LF late start
- - - - cwnd += 1
      - sstresh = 0.5 cwnd
      - cwnd = 1 if loss
    - - fast retransmission - no waiting for timer, using duplicate acks when out of sequence
      - ssthresh = cwnd = 0.5 cwnd
    - - RTT monitoring
- - - - peers by latency
      - message flooding
      - suitable for uniform p2p networks
    - - peers
      - super-peers
    - - n dimensional grid
      - messages routed parallely
- - - - hierarchical
      - flat
    - - structured
        
        distributed hash table (DHT)
        
        Chord
        
        each node and each item mapped to m-bit id
        
        data are stored at the next bigger hash
        
        scalable lookup - each node has finger table
        
        simple lookup - iterate
        
        CAN
        
        carthesian space, data is hashed, hashes placed in the space
        
        to join new node finds suitable zone to be split in half
        
        routing is done hop by hop in zones
        
        Pastry
        
        Plaxton, Rajarman, Richa Trees
        
        data storage like chord
        
        hashes stored in trees - when searching nodes try to do longest prefix match
        
        geographically diverse
        
        leaf set
        
        some sort of index that needs to be maintained
        
        Skip List
        
        Skip Graph
        
        SkipNet
        
        rings at levels
        
        nodes are part of different rings
        
        each layer in hierarchy is composed of multiple lists
        
        hierarchy of linked lists to be used as shortcuts
        
        Tree Based
        
        BATON
        
        data stored in leafs and internls
        
        adjacent and neighbor links
        
        if i have data, return data, else send to neighbor without overshooting
        
        P-grid
        
        tree structure, node responsible for data under prefix
        
        if node is not prefix, uses routing table
        
        P-Tree
        
        P-grid but balanced - B+ tree
      - unstructured
        
        hard to locate data
        
        peers keep information about data to themselves
        
        query flooding
        
        TTL not to spam network
        
        routing strategies
        
        BFS (gnutella)
        
        DFS
        
        freenet
        
        Heuristic-Based routing strategies
        
        iterative deepening
        
        bfs with depth limit
        
        directed bfs
        
        bfs but only subset of neighbours
        
        good neighbours are picked based on past performance
        
        intelligent search
        
        neighbors are ranked based on relevance to the query
        
        local indices search
        
        each node indexes its and neighbours data in radius k
        
        random walk
        
        k-walker variant
        
        first select n nodes then just 1
        
        rbfs -- like directed bfs but random
        
        adaptive probabilistic search (APS) -- k walker but not random
        
        optimistic
        
        pessimistic
        
        swapping APS
        
        weighted APS
        
        Interest based shortcuts -- peers remember who answered their queries and ask them similar queries
- - - - jednoznacnost
      - uplnost
      - verifikovatelnost
      - konzistence
      - modifikovatelnost
      - trasovatelnsot
    - - interview
      - dotaznik
      - strukturovane interview
      - workshop
      - revize
- - - - trvala promena, rostouci slozitost, vyvoj programu, invariantni spotreba prace, omezena velikost prirustku
    - - viac ludi nepomoze
  - - - 1, business modeling
      - requirements analysis
      - design
      - implementation
      - test
      - deployment
      - iteracie inkremenety, riadenie rizik, zamerany na architekturu
      - kdo udela co, kdy a jak aby dosah nejaky cil
      - zahajeni
      - 2, rozpracovani
      - konstrukce
      - zavedeni
    - - fixni cas a zdroje, variabilna funkcionalita
      - zapojenie zakaznika
      - kratke iteracie
      - priebezne automatizovane testovanie
      - agilne metodiky
        
        extreme programming
        
        feature-driven development
        
        SCRUM
        
        test-driven development
- - - - ridky
      - husty
      - viceurovnovy
      - sekundarni
    - - open/close
      - priame/nepriame
      - staticke/dynamicke
      - md5, sha1, sha2
- - - - vystaveni hlaviciek
      - rotacni zpozdeni
      - prenosova rychlost
- - - - statisticke
      - slovnikove
    - - RLE
      - Shannon-Fan
      - Huffman
      - LZ77/LZ78/LZW
- - - - FAR, FRR, FTE, FTA
  - - - Federated identity
      - single sign on
- - - - media type, encoding...
      - <tag>=<value>
  - - - on top of UDP
  - - - out of band stats and control
    - - applicaton control of transmission
      - statefu
- - - - Automatic Retransmission Request ARQ
    - - Forward Error Correction FEC
        
        Media-independent
        
        Parity Coding -- XOR
        
        Red-Solomon Coding
        
        Media-dependent -- double sending
      - interleaving
        
        shard stream parts across multiple packets
- - - - data storage for a business unit
      - in alternative architecture DW consists of decentralized data marts
    - - top-down
        
        najprv zhromazdit data do DW, potom hladat use case
      - bottom up
        
        najprv data marts potom poskladat do DW
    - - query-driven (lazy) -- dead
      - warehouse-driven -- data integrated in advance (eager)
    - - planovanie a analyza
      - dizajn infrastruktury
      - dizajn a vyvoj data marts (repeated)
    - - popisuju bisiness events
      - cislo uzivatele, cislo obchodu
      - to podla coho chceme filtrovat
      - jednopolozkova dimenzia = degradovana dimenzia
      - 4-15 dimenzii na jednu fact table
      - fakt
        
        measure
        
        mnozstvi objednavky, cena
        
        veci na sumarizovanie / priemerovanie
        
        obvykle je viac dimenzii nez faktov
        
        druhy
        
        transaction
        
        snapshot
        
        cummulative (pocet prodejov k danemu dnu)
        
        fact-less - kto, kam, kedy
        
        agregovane fakty (SUM)
        
        konsolidovane fakty (fakty z roznych zdrojov)
        
        granularita faktov (zvycajne single business transaction)
      - surrogate key
      - postup
        
        identifikovat business process
        
        stanovit granularitu
        
        identifikovat dimenzie
        
        identifikovat fakty
        
        7 Ws of DW design
      - SCD -- slowly changing dimension (overwrite, add new row...)
      - ETL process -- extract -> transform -> load
        
        data staging area
        
        data cleansing
        
        similarity join
        
        clustering
        
        parsing
        
        data quality
    - - snowflake
      - star schema
- - - - kafka, google dataflow, nifi, sqoop, flume
    - - hadoop/scylla/hbase/bigtable/rocksdb/cassandra/mongo
    - - hadoop map reduce, kafka, spark, storm
    - - hive, bigquery, redshift, snowflake, impala
    - - spark, databricks
    - - power bi, jupyter, grafana
    - - airflow
- - - - postojove vs behavioralne
      - naklady a cas
      - pocet a diverzita uzivatelov
      - laboratorium vs u pouzivatela vs remote
      - priprava
        
        postup
        
        Identifikujte a špecifikujte účel a ciele testu
        
        Identifikujte a definujte charakteristiky účastníkov
        
        Nábor testovaných osôb
        
        Metóda(y) (návrh testu)
        
        Určiť, ktoré údaje sa majú zbierať
        
        Špecifikujte testovacie prostredie a vybavenie
        
        Určite úlohy testu
        
        Pripravte si materiály
        
        Pripravte postup testovania/plán testovania
        
        List o súhlase
    - - odbornikom
      - heuristikami
      - pozorovanim
        
        premyslanie nahlas
        
        dotazniky
        
        logfiles
        
        eyetracking
- - - - SOAP, REST