急問，LVS的rear server如何設成主備模式？

急問，LVS的rear server如何設成主備模式？

現有keepalived + LVS
real server有兩台，keepalived 設置為：
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 61
    priority 200
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        10.240.1.100/22
    }
}

virtual_server 10.240.1.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    protocol TCP

    real_server 10.240.1.1 80 {
        weight 1
        TCP_CHECK {
                connect_timeout 3
        }
    }

    real_server 10.240.1.2 80 {
        weight 1
        TCP_CHECK {
                connect_timeout 3
        }
    }
}

兩台real server同時工作正常

現需要將real server的模式改為主備，
    real_server 10.240.1.1 80 {
        weight 100
        TCP_CHECK {
                connect_timeout 3
        }
    }

    real_server 10.240.1.2 80 {
        weight 0
        TCP_CHECK {
                connect_timeout 3
        }
    }

正常情況下，LVS連接都指向real server1
但是將real server關機后，繼續訪問VIP無效，不會指向real server2

請問是什麼原因啊？非常感謝

日誌中Transition to MASTER STATE    Entering MASTER STATE 是否可以看到

回復 2# kns1024wh


    關閉real server1后，日誌里只有：
Keepalived_healthcheckers: TCP connection to failed !!!
Keepalived_healthcheckers: Removing service from VS

可能我沒表達清楚，VIP是沒問題的，只是對VIP:80的訪問不會指向real server2

rear server還設置成主備？ 由前面的調試演算法完成就好了，rear server掛了，就踢出去

回復  kns1024wh


    關閉real server1后，日誌里只有：
Keepalived_healthcheckers: TCP connectio ...
ragecf 發表於 2011-11-16 14:07 http://bbs.chinaunix.net/images/common/back.gif


    還是首先來解決網路連接的問題好了

回復 5# kns1024wh


查到了，跟網路連接沒關係，man ipvsadm，明確說明了weight為0就是不接新連接請求的。

回復 6# ragecf


在主伺服器上priority 100    那 備份服務上將100改為90或者50，搞成0 ？

在keepalived.conf的手冊裡面
# for electing MASTER, highest priority wins. # to be MASTER, make 50 more than other machines. priority 100
已經說明了，這個手冊你要要看Name

/etc/keepalived/keepalived.conf - configuration file for keepalived
Description

keepalived.conf is the configuration file which describes all the keepalived keywords. keywords are placed in hierachies of blocks (and subblocks), each layer being delimited by '{' and '}' pairs.

Comments start with '#' or '!' to the end of the line and can start anywhere in a line.
Top Hierachy

GLOBAL CONFIGURATION

VRRPD CONFIGURATION

LVS CONFIGURATION
Global Configuration

contains subblocks of Global definitions and Static routes
Global definitions

global_defs # Block id { notification_email # To: { admin@example1.com ... } # From: from address that will be in header notification_email_from admin@example.com smtp_server 127.0.0.1 # IP smtp_connect_timeout 30 # integer, seconds router_id my_hostname # string identifying the machine, # (doesn't have to be hostname). }
Static routes/addresses

keepalived can configure static addresses and routes with ip (ie if addresses are not already on the machine). These addresses are NOT moved by vrrpd, they stay on the machine. If you already have IPs and routes on your machines and your machines can ping each other, you don't need this section.

The whole string is fed to ip addr add. You can truncate the string anywhere you like and let ip addr add use defaults for the rest of the string. If you just feed the string "192.168.1.1", the IP will be 192.168.1.1/32, which you probably don't want. This is different to ifconfig which will configure the IP with the standard class, here 192.168.1.1/24. The minimum string then would be the IP/netmask, eg 192.168.1.1/24

static_ipaddress { 192.168.1.1/24 brd + dev eth0 scope global ... }

The whole string is fed to ip route add. You can truncate the string allowing ip route add to use defaults.

static_routes { src $SRC_IP to $DST_IP dev $SRC_DEVICE ... src $SRC_IP to $DST_IP via $GW dev $SRC_DEVICE }
Vrrpd Configuration

contains subblocks of VRRP synchronization group(s) and VRRP instance(s)
VRRP synchronization group(s)

#string, name of group of IPs that failover together vrrp_sync_group VG_1 { group { inside_network # name of vrrp_instance (below) outside_network # One for each moveable IP. ... }

# notify scripts and alerts are optional # # filenames of scripts to run on transitions # can be unquoted (if just filename) # or quoted (if has parameters) # to MASTER transition notify_master /path/to_master.sh # to BACKUP transition notify_backup /path/to_backup.sh # FAULT transition notify_fault "/path/fault.sh VG_1"

# for ANY state transition. # "notify" script is called AFTER the # notify_* script(s) and is executed # with 3 arguments provided by keepalived # (ie don't include parameters in the notify line). # arguments # $1 = "GROUP"|"INSTANCE" # $2 = name of group or instance # $3 = target state of transition # ("MASTER"|"BACKUP"|"FAULT") notify /path/notify.sh

# Send email notifcation during state transition, # using addresses in global_defs above. smtp_alert }
VRRP instance(s)

describes the moveable IP for each instance of a group in vrrp_sync_group. Here are described two IPs (on inside_network and on outside_network), on machine "my_hostname", which belong to the group VG_1 and which will transition together on any state change. #You will need to write another block for outside_network. vrrp_instance inside_network { # Initial state, MASTER|BACKUP # As soon as the other machine(s) come up, # an election will be held and the machine # with the highest "priority" will become MASTER. # So the entry here doesn't matter a whole lot. state MASTER

# interface for inside_network, bound by vrrp interface eth0

# Ignore VRRP interface faults (default unset) dont_track_primary

# optional, monitor these as well. # go to FAULT state if any of these go down. track_interface { eth0 eth1 ... }

#default IP for binding vrrpd is the primary IP #on interface. If you want to hide location of vrrpd, #use this IP as src_addr for multicast vrrp packets. #(since it's multicast, vrrpd will get the reply #packet no matter what src_addr is used). #optional mcast_src_ip <IPADDR>

# Binding interface for lvs syncd lvs_sync_daemon_interface eth1

# delay for gratuitous ARP after transition to MASTER garp_master_delay 10 # secs, default 5

# arbitary unique number 0..255 # used to differentiate multiple instances of vrrpd # running on the same NIC (and hence same socket). virtual_router_id 51

# for electing MASTER, highest priority wins. # to be MASTER, make 50 more than other machines. priority 100

# VRRP Advert interval, secs (use default) advert_int 1 authentication { # Authentication block # PASS||AH # PASS - Simple Passwd (suggested) # AH - IPSEC (not recommended)) auth_type PASS # Password for accessing vrrpd. # should be the same for all machines. auth_pass 1234

#addresses add|del on change to MASTER, to BACKUP. #With the same entries on other machines, #the opposite transition will be occuring. virtual_ipaddress { <IPADDR>/<MASK> brd <IPADDR> dev <STRING> scope <SCOPE> label <LABEL> 192.168.200.17/24 dev eth1 192.168.200.18/24 dev eth2 label eth2:1 }

#VRRP IP excluded from VRRP #optional. #For cases with large numbers (eg 200) of IPs #on the same interface. To decrease the number #of packets sent in adverts, you can exclude #most IPs from adverts. #The IPs are add|del as for virtual_ipaddress. virtual_ipaddress_excluded { <IPADDR>/<MASK> brd <IPADDR> dev <STRING> scope <SCOPE> <IPADDR>/<MASK> brd <IPADDR> dev <STRING> scope <SCOPE> ... } # routes add|del when changing to MASTER, to BACKUP virtual_routes { # src <IPADDR> <IPADDR>/<MASK> via|gw <IPADDR> dev <STRING> scope <SCOPE> tab src 192.168.100.1 to 192.168.109.0/24 via 192.168.200.254 dev eth1 192.168.110.0/24 via 192.168.200.254 dev eth1 192.168.111.0/24 dev eth2 192.168.112.0/24 via 192.168.100.254 }

# VRRP will normally preempt a lower priority # machine when a higher priority machine comes # online. "nopreempt" allows the lower priority # machine to maintain the master role, even when # a higher priority machine comes back online. # NOTE: For this to work, the initial state of this # entry must be BACKUP. nopreempt

# Seconds after startup until preemption # (if not disabled by "nopreempt"). # Range: 0 (default) to 1,000 # NOTE: For this to work, the initial state of this # entry must be BACKUP. preempt_delay 300 # waits 5 minutes

# Debug level, not implemented yet. debug

# notify scripts, alert as above notify_master <STRING>|<QUOTED-STRING> notify_backup <STRING>|<QUOTED-STRING> notify_fault <STRING>|<QUOTED-STRING> notify <STRING>|<QUOTED-STRING> smtp_alert }
Lvs Configuration

contains subblocks of Virtual server group(s) and Virtual server(s)

The subblocks contain arguments for ipvsadm(8). A knowlege of ipvsadm(8) will be helpful here.
Virtual server group(s)

# optional # this groups allows a service on a real_server # to belong to multiple virtual services # and to be only health checked once. # Only for very large LVSs. virtual_server_group <STRING> { #VIP port <IPADDR> <PORT> <IPADDR> <PORT> ... # # <IPADDR RANGE> has the form # XXX.YYY.ZZZ.WWW-VVV eg 192.168.200.1-10 # range includes both .1 and .10 address <IPADDR RANGE> <PORT># VIP range VPORT <IPADDR RANGE> <PORT> ... fwmark <INT> # fwmark fwmark <INT> ... }
Virtual server(s)

A virtual_server can be a declaration of one of

vip vport (IPADDR PORT pair)
fwmark <INT>
(virtual server) group <STRING>
    #setup service virtual_server IP port | virtual_server fwmark int | virtual_server group string { # delay timer for service polling delay_loop <INT>

    # LVS scheduler lb_algo rr|wrr|lc|wlc|lblc|sh|dh # LVS forwarding method lb_kind NAT|DR|TUN # LVS persistence timeout, sec persistence_timeout <INT> # LVS granularity mask (-M in ipvsadm) persistence_granularity <NETMASK> # Only TCP is implemented protocol TCP # If VS IP address is not set, # suspend healthchecker's activity ha_suspend

    # VirtualHost string for HTTP_GET or SSL_GET # eg virtualhost www.firewall.loc virtualhost <STRING>

    # Assume silently all RSs down and healthchecks # failed on start. This helps preventing false # positive actions on startup. Alpha mode is # disabled by default. alpha

    # On daemon shutdown, consider quorum and RS # down notifiers for execution, where appropriate. # Omega mode is disabled by default. omega

    # Minimum total weight of all live servers in # the pool necessary to operate VS with no # quality regression. Defaults to 1. quorum <INT>

    # Tolerate this much weight units compared to the # nominal quorum, when considering quorum gain # or loss. A flap dampener. Defaults to 0. hysteresis <INT>

    # Script to launch when quorum is gained. quorum_up <STRING>|<QUOTED-STRING>

    # Script to launch when quorum is lost. quorum_down <STRING>|<QUOTED-STRING>

    # setup realserver(s)

    # RS to add when all realservers are down sorry_server <IPADDR> <PORT>

# one entry for each realserver

    real_server <IPADDR> <PORT> { # relative weight to use, default: 1 weight <INT> # Set weight to 0 # when healthchecker detects failure inhibit_on_failure
    # Script to launch when healthchecker # considers service as up. notify_up <STRING>|<QUOTED-STRING> # Script to launch when healthchecker # considers service as down. notify_down <STRING>|<QUOTED-STRING>

    # pick one healthchecker # HTTP_GET|SSL_GET|TCP_CHECK|SMTP_CHECK|MISC_CHECK

    # HTTP and SSL healthcheckers HTTP_GET|SSL_GET { # A url to test # can have multiple entries here url { #eg path / , or path /mrtg2/ path <STRING> # healthcheck needs status_code # or status_code and digest # Digest computed with genhash # eg digest 9b3a0c85a887a256d6939da88aabd8cd digest <STRING> # status code returned in the HTTP header # eg status_code 200 status_code <INT> } #IP, tcp port for service on realserver connect_port <PORT> bindto <IPADDR> # Timeout connection, sec connect_timeout <INT> # number of get retry nb_get_retry <INT> # delay before retry delay_before_retry <INT> } #HTTP_GET|SSL_GET

    #TCP healthchecker (bind to IP port) TCP_CHECK { connect_port <PORT> bindto <IPADDR> connect_timeout <INT> } #TCP_CHECK

    # SMTP healthchecker SMTP_CHECK { # An optional host interface to check. # If no host directives are present, only # the ip address of the real server will # be checked. host { # IP address to connect to connect_ip <IP ADDRESS> # Optional port to connect to if not # the default of 25 connect_port <PORT> # Optional interface to use to # originate the connection bindto <IP ADDRESS> } # Connection and read/write timeout # in seconds connect_timeout <INTEGER> # Number of times to retry a failed check retry <INTEGER> # Delay in seconds before retrying delay_before_retry <INTEGER> # Optional string to use for the smtp HELO request helo_name <STRING>|<QUOTED-STRING> } #SMTP_CHECK

    #MISC healthchecker, run a program MISC_CHECK { # External system script or program misc_path <STRING>|<QUOTED-STRING> # Script execution timeout misc_timeout <INT>

    # If set, exit code from healthchecker is used # to dynamically adjust the weight as follows: # exit status 0: svc check success, weight # unchanged. # exit status 1: svc check failed. # exit status 2-255: svc check success, weight # changed to 2 less than exit status. # (for example: exit status of 255 would set # weight to 253) misc_dynamic } } # realserver defn } # virtual service

Author

Joseph Mack.
Information derived from doc/keepalived.conf.SYNOPSIS, doc/samples/keepalived.conf.* and Changelog by Alexandre Cassen for keepalived-1.1.4, and from HOWTOs by Adam Fletcher and Vince Worthington.
See Also

ipvsadm(8), ip --help.
Referenced By
genhash(1), keepalived(8)

回復  ragecf


在主伺服器上priority 100    那 備份服務上將100改為90或者50，搞成0 ？

在keepali ...
kns1024wh 發表於 2011-11-17 17:49 http://bbs.chinaunix.net/images/common/back.gif

哥們，我一直說的是要求real server分主備，是靠weight設置的
您說的priority是用於direct server分主備的

回復 8# ragecf


    realserver 一共幾台要做主備。
   
  前段是lvs 的一個作用就是 realserver的健康檢查 監控移除問題節點。
  
  如果要做realsever的主備 ，可以根據需要使用heartbeat，並且要發布浮動IP用作lvs的調度節點調用的realserver

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