Proxysql scheduler tests

Scenario:
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Scenario 1 writer 3 readers 
    writerIsAlsoReader =1 
    FailBack = 0
    with retry Down = 2
----------------------------------
Test : PXC maint 
Expectations: 
    Writer will go in OFFLINE_SOFT
    Reader will become writer in respect to the weight as declared in the 8000 HG
    On end of maintenance NO failback is expected
    If node is reader then OFFLINE_SOFT then failback
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Test : wsrep_desync (or any state <> 4)
Expectations: 
    Node will go in OFFLINE_SOFT only if HG size > 1
    
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Test : wsrep_reject_queries <> none
Expectations: node is moved to HG 9000

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Test : on SHUNNED
Expectations: node is moved to HG 9000 if back online Reader is add back Writer attempt to come back if no writer

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Test : on Crash or network down
Expectations: node is moved to HG 9000

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Test : Add node
Expectations: when a new node comes online and is declared in the 8000 HG, it is added to the corresponding HG (writer only if it fits)


=======================================
Scenario 1 writer 3 readers
    writerIsAlsoReader =1
    FailBack = 1
    with retry Down = 2
----------------------------------
Test : PXC maint
Expectations:
    Writer will go in OFFLINE_SOFT
    Reader will become writer in respect to the weight as declared in the 8000 HG
    On end of maintenance failback is expected
    If node is reader then OFFLINE_SOFT then failback
----------------------------------------------------------
Test : wsrep_desync (or any state <> 4)
Expectations:
    Node will go in OFFLINE_SOFT only if HG size > 1
    failback is expected
----------------------------------------------------------
Test : wsrep_reject_queries <> none
Expectations: node is moved to HG 9000
                failback is expected
----------------------------------------------------------
Test : on SHUNNED
Expectations: node is moved to HG 9000 if back online Reader is add back Writer attempt to come back if no writer
                failback is expected
----------------------------------------------------------
Test : on Crash or network down
Expectations: node is moved to HG 9000
                failback is expected
----------------------------------------------------------
Test : Add node
Expectations: when a new node comes online and is declared in the 8000 HG, it is added to the corresponding HG (writer only if it fits)
                failback is expected


=======================================
Scenario 1 writer 3 readers
    writerIsAlsoReader <>1
    FailBack = 0
    with retry Down = 2
    In all tests Writer is not a reader unless not reader left. This works ONLY if all nodes have wsrep_sync_wait = 3 or >
----------------------------------
Test : No readers left
Expectations: Writer will become also reader

----------------------------------------------------------
Test : PXC maint
Expectations:
    Writer will go in OFFLINE_SOFT
    Reader will become writer in respect to the weight as declared in the 8000 HG
    On end of maintenance NO failback is expected
    If node is reader then OFFLINE_SOFT then failback
----------------------------------------------------------
Test : wsrep_desync (or any state <> 4)
Expectations:
    Node will go in OFFLINE_SOFT only if HG size > 1

----------------------------------------------------------
Test : wsrep_reject_queries <> none
Expectations: node is moved to HG 9000

----------------------------------------------------------
Test : on SHUNNED
Expectations: node is moved to HG 9000 if back online Reader is add back Writer attempt to come back if no writer

----------------------------------------------------------
Test : on Crash or network down
Expectations: node is moved to HG 9000

----------------------------------------------------------
Test : Add node
Expectations: when a new node comes online and is declared in the 8000 HG, it is added to the corresponding HG (writer only if it fits)


=======================================
Scenario 2 writer (or more), 3 readers
    writerIsAlsoReader =1
    FailBack = 0
    with retry Down = 2
----------------------------------
Test : PXC maint
Expectations:
    Writer will go in OFFLINE_SOFT
    Reader will become writer in respect to the weight as declared in the 8000 HG
    On end of maintenance failback is expected
    If node is reader then OFFLINE_SOFT then failback
----------------------------------------------------------
Test : wsrep_desync (or any state <> 4)
Expectations:
    Node will go in OFFLINE_SOFT only if HG size > 1
    On state = 4 failback
----------------------------------------------------------
Test : wsrep_reject_queries <> none
Expectations: node is moved to HG 9000
              Failback when reject_queries = none

----------------------------------------------------------
Test : on SHUNNED
Expectations: node is moved to HG 9000
                if back online failback

----------------------------------------------------------
Test : on Crash or network down
Expectations: node is moved to HG 9000
                failback on recover

----------------------------------------------------------
Test : Add node
Expectations: when a new node comes online and is declared in the 8000 HG, it is added to the corresponding HG (writer only if it fits)

