Oracle MTS的相关问题

MTS是ORACLE SERVER的一个可选的配置选择，是相对DEDICATE方式而言，它最大的优点是在以不用增加物理资源（内存）的前提下支持更多的并发的连接。

Joseph C.Johnson以餐馆给出一个MTS的形象的比喻　　51Testing软件测试网&A Xg2B#T?
　　假设ORACLE是一家餐馆，当你走进一家餐馆时你感觉最舒服的服务方式就是有一个专门的waiter来为你服务，而不管餐馆中来了多少人，她只对你请求应答，这是DEDICTE的处理方式，也就是说每一个ORACLE客户端的连接都有一个专门的服务进程来为它服务。而大部的餐馆的服方式都不是一对一的，当你走进的时侯，你就被指定了一个waiter，她也可能为其它桌服着务，这对于餐馆来说是最有利的，因为他们可以服务更多的客人而不需要增加他们的员工。这样对你来说也可能是不错的，如果餐馆不是太忙，她服务的客人的请求都很简短且容易完成，你的感觉也好像自己拥有一个专门的waiter，waiter把你的ORDER转给厨师，然后把做好的菜拿给你，这就是MTS的处理方式，这些共享的waiters我们叫她们为Dispatchers，厨师我们则叫他们为Shared Server Processes。

 

1.  Oracle Multi-Threaded Server Architecture.
#nzD+f2H"M
\*YJ0----------------------------------------------51Testing软件测试网1Z-G s_,R0Ge
51Testing软件测试网X2} p"J.~ G
                            +-----------+   user
g1B-x)X e0                           +-----------+|   processes
#tqTpr\E$W0                           |           ||51Testing软件测试网S1S1ru'oR
                           |APPLICATION||
U]5@8u} T0                           |   CODE    ||51Testing软件测试网i/IGUu8X
                           |           |+51Testing软件测试网zuE\ck
                           +-----------+
/cD CZG0                                /|\

OrCg(tf'yb0                                 |                     CLIENT
4U)jLs M0          - - - - - - - - - - - - - - - - - - - - - - - - - - - - -51Testing软件测试网zAo[wl"@`4L
                                 |                     SERVER
;b6\dV$J;m%yP&PWp6@],f0                                \|/51Testing软件测试网*PuW$U*H
                       +----------------------------------+51Testing软件测试网:U?qt5xt!e0i
                      +----------------------------------+|51Testing软件测试网*_E6bhP+p
                      |                                  ||
5i-d'b9z9A3~i"u0                      |       DISPATCHER PROCESSES       || 
'^dn lF0                      |                                  |+  
,m'H%i{.wi0                      +----------------------------------+    
oC?i-v A
U0                        |                             /|\51Testing软件测试网:N/|J7e'zv
                        |                              |
T;B]"G we!s'p0                        |     +-----------+            |51Testing软件测试网TI @V!?
                        |    +-----------+| shared     |
E9[:W(a
k5lm0                        |   +-----------+|| server     |
}-l&@ju$e
jMM"z0                        |   |  ORACLE   ||+ processes  |
X~jDR'A9p`)O"{0                        |   |SERVER CODE|+             |51Testing软件测试网'RaD"T_4{8s kRkp
                        |   +-----------+              |
'D;Wl$T$T8p.}Js0                        |    /|\ /|\  |                |
(jy+px f{0                        |     |   |   |                |
J*f+K&?lV"{/evq K0                        |     |   |   |                |51Testing软件测试网)~JL0H4c)}
                        |     |  \|/  |                |51Testing软件测试网x*Y/l's4]-SG$^
        +---------------|-----|-------|----------------|-------+51Testing软件测试网Se;yF;M&Oh#e1ih8aX
        |              \|/    |      \|/               |       |51Testing软件测试网V,t;[^;sZHU z
        |   +-------------------+   +----------------------+   |
X
W3m/A_1b5y#I0        |   |     REQUEST       |   |   RESPONSE QUEUES    |   |
2T+V|*fte1r0        |   |     QUEUES        |   +----------------------+   |51Testing软件测试网5U+l4j _reY
        |   +-------------------+                              |
2]&pI0w-l'K
O_T(e0        |                  SYSTEM GLOBAL AREA                  |
u
^FG6x$[(\+s0        |                                                      |51Testing软件测试网"}Rx;q4\-l8Um4L
        +------------------------------------------------------+
:u1TCSTj051Testing软件测试网7~A ?,_7B~ R
V#w&]U8B
Client Connections to MTS51Testing软件测试网_$X$[X0R+MaV2l+K
    ~~~~~~~~~~~~~~~~~~~~~~~~~
+D2}{aA({p0 A client process wanting to connect to an Oracle instance using MTS51Testing软件测试网3X1F1Th
p,s
 should go through the following steps:

  a) Call the listener51Testing软件测试网0P,@4Ah @yIv
  b) The listener tells it to call back on the address where51Testing软件测试网o A.r4O8wS
[4]
     the dispatcher is listening (a REDIRECT)51Testing软件测试网~\o7x&\7R
Kz
  c) The client calls the dispatcher and establishes a connection.51Testing软件测试网5D#hHt*q0[-h
  d) The dispatcher now has a CLIENT connection ESTABLISHED and
g(V9}i!Y`B1gr0     will also continue to listen for any new connections.
%H8?hjdWQ-XH#pb0  e) The client sends a SQL message to the dispatcher.
6}t*f$vzCJ0  f) The dispatcher unwraps this message packet and places the51Testing软件测试网 [m:ehSakF4R3W.U
     request onto a queue in the SGA (System Global Area).
uP0Se1V5X^}~b0     This queue has NOTHING to do with SQL*Net. The SQL*Net51Testing软件测试网l-a$pk&N#h3P
     layer ends in the dispatcher.51Testing软件测试网a+i?V!e
  g) A shared server will pick up the request from the SGA queue
UP&~1O&\nP[0     and process it. When there is any result this is placed51Testing软件测试网$C%]"_Ws
     on a separate queue in the SGA ready for the dispatcher.51Testing软件测试网Z
ZN(W @:ln@
  h) The dispatcher picks up the response message from the SGA51Testing软件测试网tm`m[vwF
     and wraps this into a SQL*Net message. This is passed51Testing软件测试网
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     back to the client.

 

Solution Description:51Testing软件测试网e!I'oIad6u
=====================
(HY(C:OoA(Z#R,h
G0 
F5|&U'_|0Look at the "init.ora" parameter MTS_DISPATCHERS.
2aVUo*R0QQ x0 
x"`Bs&jw slVK0MTS_DISPATCHERS defines the number of dispatchers created when the instance51Testing软件测试网z&ob(t9fRO
starts up. If this is set to zero, or is null (default value), then you are NOT
bT%gJ#z{2y%c"eW0using MTS.

If MTS_DISPATCHERS is greater than zero, then check these other "init.ora"
GFpa
f0zT)r-F4^9r)R0parameters for valid values:

   MTS_MAX_DISPATCHERS  Maximum number of dispatchers
&kM*x.M1qr&a*d0   MTS_SERVERS  Number of server processes created at startup51Testing软件测试网1jJS,~(\t aZ
   MTS_MAX_SERVERS  Maximum number of shared server processes
K(i0UE|b0   MTS_SERVICE  SID
kQo-u^0   MTS_LISTENER_ADDRESS  Configuration of the listener51Testing软件测试网)C]GN UN*|y8l
 

Solution Explanation:51Testing软件测试网4a!](Qw(gx
=====================
J;Ul mC0 
m5E[Zv&s"hm0These other "init.ora" parameters may have valid values, but if MTS_DISPATCHERS
XQj/hotK(D0is zero or null, MTS is not being used.

The main parameters required to start MTS are:

  o MTS_SERVICE - This parameter establishes the name of the MTS service
|A sY;_0    that clients connect to, in order for the dispatchers to handle requests.
o;Ie C0}2h q#} S+W rg0   51Testing软件测试网)B+~-O/vnC
vf
  o MTS_DISPATCHERS - Dispatchers are detached processes that handle client51Testing软件测试网.yT_h'F'TybW,Q'Wj
    process requests and communicate them to server processes for execution.

    This parameter defines the number of dispatchers to startup for
)?&LkR-l{&~0    each protocol that is configured for MTS.  For example,51Testing软件测试网%U*DwC*U't+g
 
B"kQ\(vzy2d,Q0         mts_dispatchers = "ipc, 2"

  o MTS_SERVERS - This is the number of shared server processes that51Testing软件测试网:j`IC_
    start at instance startup time.  Shared servers service the51Testing软件测试网7W Qv[(t9tj%C
    client requests passed on to them by the dispatchers.

  o MTS_LISTENER_ADDRESS - This is the full address for dispatchers to listen
^DeBSD3l0    on, and is the same as the address configured in the TNS listener.  The
fwm/K2ny8Yt0    address specification is protocol-specific.  For example:

         mts_listener_address = "(address=(protocol=ipc)(key=sw))"

先在主机命令行$ lsnrctl services;

"D000" established:0 refused:0 current:1 max:972 state:ready
jw"y&[)Y&RG(Q0         DISPATCHER <machine: db1, pid: 3950>
\/NdWw0         (ADDRESS=(PROTOCOL=tcp)(HOST=eagle1)(PORT=33166))；

查看dispather的监听端口号——33166。(dispather进程名称一般是 ora_dNNN_SID,NNN in (000-999))

在client端的tnsname.ora中，注意：

TODB_MTS =51Testing软件测试网#s^acr8Ur*Pb
  (DESCRIPTION =
)}6W%TzX;P5md0    (ADDRESS_LIST =51Testing软件测试网J
l2OeZ)PCE
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.2)(PORT = 33166))
[v#KD?5Y|0    )51Testing软件测试网0i#]%Sq
B2A
    (CONNECT_DATA =
n.ttr\D"Vn-t0     (SERVER = SHARED)
K/\x$f$Ax4Z0      (SERVICE_NAME = dbname)
C$Z0X_[-\0    )
X;W1U!L ] Vr{0  )

这样可以解决ora-12520问题(当然这只是解决方法之一)

A：不是。如果硬件好点，建议使用Delicated模式。biti语录：“我是能不用MTS就不用”

A：可以。

MTS => Delicated

Reset the MTS Parameters in init.ora and reopen your DB.

Delicated => MTS

Added the MTS Parameters in init.ora and reopen your DB.

A：可以。(SERVER = Delicated)即可。反之则不行。

A：不是。

A：目前不支持。