使用并行化来提高timesten的replication和awt性能

                                                     使用并行化来提高timesten的replication和awt性能

          在timesten 11.2.0.2版本之前，每个复制只有一个transmitier和receiver对来传送和接收复制的日志，一个receiver线程刷新awt数据到

oracle数据中.在一个繁忙的系统中由于单个线处理能力有限，这可会带来性能瓶劲，在11.2.0.2后，引入了并行复制的概念.可以在DSN中定义多个
transmitier和receiver对

[timesten@master1 ~]$ ttstatus | egrep  "RECEIVER|TRANS"
Replication     6073    0x000000001eed0920  TRANSMITTER(M):1116182848      2031
Replication     6073    0x000000001ef25420  TRANSMITTER(M):1119332672      2030
Replication     6073    0x000000001efcd740  RECEIVER:1091275072            2029

DSN参数
ReplicationParallelism  定义了transmitter和receiver对，值2-32，尽量小于logbufparallelism,不能使用return receipt和two safe
cacheawtparallelism 如果不设置为replicationparallelism的2倍，如果配置了，则是本身的值

这两个参数修改需要重新创建数据库。

ReplicationParallelism=8
CacheAwtParallelism=8

在备库上可以看到有8个连接了
[timesten@tt2 abc]$ ttstatus | egrep  "RECEIVER|TRANS"
Replication     14012   0x0000000016ecfbf0  TRANSMITTER(M):1118984512       531
Replication     14012   0x0000000016f963e0  RECEIVER:1156782400             517
Replication     14012   0x0000000017002b90  TRANSMITTER(S):1122134336       529
Replication     14012   0x0000000017077d50  TRANSMITTER(S):1125284160       528
Replication     14012   0x00000000170cc720  TRANSMITTER(S):1128433984       527
Replication     14012   0x00000000171210f0  TRANSMITTER(S):1131583808       526
Replication     14012   0x0000000017175ac0  TRANSMITTER(S):1134733632       525
Replication     14012   0x00000000171ca490  TRANSMITTER(S):1137883456       524
Replication     14012   0x000000001721ee60  TRANSMITTER(S):1141033280       523
Replication     14012   0x00000000173590e0  RECEIVER:1150482752             518
Replication     14012   0x00000000173e5e60  RECEIVER:1084729664             530
Replication     14012   0x000000001748ad40  RECEIVER:1094248768             520
Replication     14012   0x00000000175bcad0  RECEIVER:1144183104             521
Replication     14012   0x0000000017654ce0  RECEIVER:1078348096             522
Replication     14012   0x00000000176f66d0  RECEIVER:1147332928             519
Replication     14012   0x00000000301372c0  RECEIVER:1153632576             516

在log holds有8个对像
Command> call ttlogholds;
< 0, 3727360, Checkpoint                    , frank.ds0 >
< 0, 14731264, Checkpoint                    , frank.ds1 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:0 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:1 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:2 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:3 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:4 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:5 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:6 >
< 0, 15651176, Replication                   , 192.168.233.52:FRANK:7 >

在目标端有一个sort的区域，通过对接收过来的日志进行排序，从而在备库上和主库上进行一致性的顺序提交.