Fix possible pipeline connections leak

[ING-XIAOJIAN]

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Description of change

When Executing "n.write()" may generate some unknown errors(e.g. DataError), which could result in the connection not being released, finally lead to connection leak.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (18bb016) 92.05% compared to head (adc8893) 92.00%.
Report is 2 commits behind head on master.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3104      +/-   ##
==========================================
- Coverage   92.05%   92.00%   -0.06%     
==========================================
  Files         128      128              
  Lines       33195    33197       +2     
==========================================
- Hits        30557    30542      -15     
- Misses       2638     2655      +17     

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[dvora-h]

@ING-XIAOJIAN thanks for suggestion, looks good, but WDYT about:

    try:
        node_commands = nodes.values()
        for n in node_commands:
            n.write()

        for n in node_commands:
            n.read()
    finally:
        for n in nodes.values():
            n.connection_pool.release(n.connection)

[ING-XIAOJIAN]

@ING-XIAOJIAN thanks for suggestion, looks good, but WDYT about:

    try:
        node_commands = nodes.values()
        for n in node_commands:
            n.write()

        for n in node_commands:
            n.read()
    finally:
        for n in nodes.values():
            n.connection_pool.release(n.connection)

I naively think "n.read" never generates some unknown errors,
I will take your suggestion.

[dvora-h]

I agree that there is less chance to get an error in the reading, but I prefer to cover that as well just to be safe

[dvora-h]

@ING-XIAOJIAN Can you fix the linters or wants me to do it?

[ING-XIAOJIAN]

@ING-XIAOJIAN Can you fix the linters or wants me to do it?

I already fixed those linters

[dvora-h]

Thanks!

[dvora-h]

Can you delete this lines from the comment and move the explanations of this lines before them?

[ING-XIAOJIAN]

I already fixed this. could you review it again?

[bcmills]

This comment seems out-of-date — isn't it explaining why not to do exactly what this change is doing?

It should probably be update to explain why this is safe, not why it isn't. 😅