* add show create view clause support

* remove debug code

* add ut

The response TxnMeta needs to be checked only if TxnError is not empty, otherwise the error message returned will be incorrect

Approved by: @reusee, @lni

frontend: set session request contexts

Approved by: @daviszhen

remove `system_vars_config.toml`

Approved by: @daviszhen

Approved by: @fengttt

Approved by: @nnsgmsone, @aressu1985

Stop directing gossip traffics to service address as that could confuse some tests.

Approved by: @fengttt, @zhangxu19830126

read when ts is equal

Approved by: @XuPeng-SH, @fengttt

* add standalone cn config

* fix typo

* debug log for default

* support mo-service-standalone ci

Co-authored-by: ouyuanning <52741323@qq.com>

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: maomao <77312370+sukki37@users.noreply.github.com>

fix bug: insert/update/delete is not supported in view, but no error was thrown

Approved by: @fengttt, @aunjgr, @aressu1985

Approved by: @fengttt, @XuPeng-SH

Support client-to-server encrypted communication.

the follow feature not supported yet:
1、auto reload cert/key file
2、upgrade TLS base user's tls_option（eg: CREATE USER 'jeffrey'@'localhost' REQUIRE SSL;).

and test case can't pass in Ubuntu+golang1.9 in docker。 so I add an issue(#4656 ) for that.

Approved by: @daviszhen

Added a new UseTeeLogDB option to Log Service config. This allows selected tests to enable tee based LogDB for testing while making sure that it is not used in standalone mode testing.

Approved by: @reusee

txnstorage: add IsolationPolicy; refactor conflict error types

Approved by: @zhangxu19830126

First read does not return txnmeta, so client returns a TxnError

Approved by: @reusee, @lni

dnservice: init txn/storage/mem in MEM backend. rename old MEM to MEMKV

Approved by: @zhangxu19830126

prepare for FileService flush into csv file.
- mv trace *config struct into trace/config.go
- refactor trace_idd/transaction_id/session_id be uuid as [16]byte
- refactor trace.NoReportFiled() as logutil.NoReportFiled()

Approved by: @aptend, @reusee, @daviszhen, @nnsgmsone, @zhangxu19830126, @fengttt

fileservice: allow setting shared config profile in S3 fs

Approved by: @zhangxu19830126, @nnsgmsone

Retry start DNShard if failed

Approved by: @reusee

Approved by: @reusee

Add createAt column for mo_database and mo_tables

Approved by: @daviszhen, @XuPeng-SH

Approved by: @aressu1985

add more BVT test for prepare clause

Approved by: @aressu1985

txnstorage: add ErrStaleWrite, ErrStaleRead

Approved by: @fengttt, @zhangxu19830126, @lni

Approved by: @dengn

Implement `intersect all` operator

Approved by: @nnsgmsone, @iamlinjunhong, @ouyuanning, @aunjgr, @aressu1985

Support create txn sender by config. And DN and CN service can share this implementation.

Approved by: @nnsgmsone, @reusee, @lni

fix the bug while external scan occur the NULL value in char&varcahr data type

Approved by: @nnsgmsone

txn: add error return to TxnClient.New

Approved by: @daviszhen, @XuPeng-SH, @zhangxu19830126, @lni

Approved by: @dengn

cnservice: initialize hakeeper client, txn sender, txn client lazily

Approved by: @zhangxu19830126, @nnsgmsone

Co-authored-by: bRong Njam <longran1989@gmail.com>
Co-authored-by: fengttt <fengttt@gmail.com>

This commit replaces `os.Setenv` with `t.Setenv` in tests. The
environment variable is automatically restored to its original value
when the test and all its subtests complete.

Reference: https://pkg.go.dev/testing#T.Setenv


Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

Support trace context transfer via morpc framework

Approved by: @reusee

cnservice: add memory engine to service.initEngine

txnengine: add ShardToSingleStatic

Approved by: @nnsgmsone

Approved by: @yingfeng

fileservice: add FileService.Name

fileservice: add FileServices; add Get

fileservice: support named path

dnservice: replace store.localFS,s3FS with store.fs,metadataFS

Approved by: @zhangxu19830126, @cnutshell, @nnsgmsone

fix set clause bug: when set uint64 value in sql, but save int64 to session.

Approved by: @daviszhen, @aressu1985

avoid import cycle: trace -> pkg/config -> pkg/txn/client -> pkg/common/morpc -> trace

Approved by: @zhangxu19830126, @fengttt