optimize: lazily load branch transactions and task scheduling

[funky-eyes]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

xa模式对同一条数据增加库存 100并发 150秒
优化版db 模式

Concurrency Level:      100
Time taken for tests:   150.001 seconds
Complete requests:      8577
Failed requests:        0
Total transferred:      934893 bytes
HTML transferred:       34308 bytes
Requests per second:    57.18 [#/sec] (mean)
Time per request:       1748.872 [ms] (mean)
Time per request:       17.489 [ms] (mean, across all concurrent requests)
Transfer rate:          6.09 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.3      0       2
Processing:    82 1737 145.3   1732    3441
Waiting:       53 1737 145.3   1731    3441
Total:         82 1737 145.3   1732    3442

Percentage of the requests served within a certain time (ms)
  50%   1732
  66%   1765
  75%   1803
  80%   1830
  90%   1876
  95%   1928
  98%   2000
  99%   2023
 100%   3442 (longest request)

redis 模式

Concurrency Level:      100
Time taken for tests:   150.021 seconds
Complete requests:      5855
Failed requests:        0
Total transferred:      638195 bytes
HTML transferred:       23420 bytes
Requests per second:    39.03 [#/sec] (mean)
Time per request:       2562.264 [ms] (mean)
Time per request:       25.623 [ms] (mean, across all concurrent requests)
Transfer rate:          4.15 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.4      0       1
Processing:    80 2543 398.0   2712    3346
Waiting:       51 2542 398.0   2711    3346
Total:         81 2543 398.0   2712    3346

Percentage of the requests served within a certain time (ms)
  50%   2712
  66%   2757
  75%   2781
  80%   2801
  90%   2899
  95%   3017
  98%   3116
  99%   3182
 100%   3346 (longest request)

原版redis模式

Concurrency Level:      100
Time taken for tests:   150.023 seconds
Complete requests:      5306
Failed requests:        0
Total transferred:      578354 bytes
HTML transferred:       21224 bytes
Requests per second:    35.37 [#/sec] (mean)
Time per request:       2827.430 [ms] (mean)
Time per request:       28.274 [ms] (mean, across all concurrent requests)
Transfer rate:          3.76 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.4      0       2
Processing:    73 2796 432.9   2928    3465
Waiting:       43 2795 432.9   2927    3465
Total:         74 2796 433.0   2928    3466

Percentage of the requests served within a certain time (ms)
  50%   2928
  66%   2965
  75%   2999
  80%   3019
  90%   3140
  95%   3225
  98%   3332
  99%   3408
 100%   3466 (longest request)

原版db模式

Concurrency Level:      100
Time taken for tests:   150.000 seconds
Complete requests:      8598
Failed requests:        0
Total transferred:      937182 bytes
HTML transferred:       34392 bytes
Requests per second:    57.32 [#/sec] (mean)
Time per request:       1744.594 [ms] (mean)
Time per request:       17.446 [ms] (mean, across all concurrent requests)
Transfer rate:          6.10 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.3      0       2
Processing:    87 1733 131.1   1735    2166
Waiting:       59 1733 131.1   1735    2166
Total:         87 1733 131.1   1735    2166

Percentage of the requests served within a certain time (ms)
  50%   1735
  66%   1754
  75%   1773
  80%   1795
  90%   1850
  95%   1913
  98%   1982
  99%   2034
 100%   2166 (longest request)

Ⅱ. Does this pull request fix one issue?

fixes #4337

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-commenter]

Codecov Report

Merging #4086 (dd8d188) into develop (f1be649) will increase coverage by 0.07%.
The diff coverage is 79.76%.

@@              Coverage Diff              @@
##             develop    #4086      +/-   ##
=============================================
+ Coverage      48.85%   48.93%   +0.07%     
- Complexity      3935     3952      +17     
=============================================
  Files            733      733              
  Lines          24900    24968      +68     
  Branches        3068     3088      +20     
=============================================
+ Hits           12166    12219      +53     
- Misses         11452    11454       +2     
- Partials        1282     1295      +13     

Impacted Files	Coverage Δ
...c/main/java/io/seata/common/ConfigurationKeys.java	0.00% <ø> (ø)
...ommon/src/main/java/io/seata/common/Constants.java	100.00% <ø> (ø)
...er/console/controller/BranchSessionController.java	100.00% <ø> (ø)
...in/java/io/seata/server/session/BranchSession.java	79.16% <ø> (-0.15%)	⬇️
...ver/storage/db/lock/DataBaseDistributedLocker.java	0.86% <0.00%> (ø)
.../server/store/AbstractTransactionStoreManager.java	33.33% <0.00%> (-6.67%)	⬇️
...io/seata/server/store/TransactionStoreManager.java	86.66% <ø> (ø)
...ava/io/seata/server/transaction/saga/SagaCore.java	2.72% <ø> (ø)
...in/java/io/seata/server/session/SessionHolder.java	51.44% <50.00%> (-0.05%)	⬇️
...o/seata/server/storage/redis/lock/RedisLocker.java	37.43% <62.50%> (-0.14%)	⬇️
... and 17 more

[lgtm-com]

This pull request introduces 1 alert when merging e1a8386 into 54b394e - view on LGTM.com

new alerts:

• 1 for Dereferenced variable may be null

[caohdgege]

LGTM

[slievrly]

Whether this logic can be deleted ？