Review Request 62285: Added tombstone flag to NOP log action.

2017-09-13 Thread Ilya Pronin 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/62285/
---

Review request for mesos and Jie Yu.


Bugs: MESOS-7973
https://issues.apache.org/jira/browse/MESOS-7973


Repository: mesos


Description
---

NOP action is used as a filler for holes in the "fill" procedure and as
the action in a response to a promise request for a truncated position.
The tombstone flag is introduced so that replicas are able to
distinguish the truncated action from a real NOP.


Diffs
-

  src/log/leveldb.cpp 5310a123b0fb25f240429722b676fe46174cb2ce 
  src/log/replica.cpp 39f2879b2e37c1ca9a9f987ce0a3b83e8dbc9b43 
  src/messages/log.proto ca740bd011147f8f48cc5dfcacefa5fdbd95ccd0 
  src/tests/log_tests.cpp f9f9400c901152779ae0ebfe74cf8f7aac1d3396 


Diff: https://reviews.apache.org/r/62285/diff/1/


Testing
---

Added a test that verifies that a replica correctly handles the tombstone NOP. 
Ran `make check`.


Thanks,

Ilya Pronin

Re: Review Request 62285: Added tombstone flag to NOP log action.

2017-12-21 Thread Jie Yu 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/62285/#review194367
---


Ship it!




Ship It!

- Jie Yu


On Sept. 25, 2017, 1:05 p.m., Ilya Pronin wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/62285/
> ---
> 
> (Updated Sept. 25, 2017, 1:05 p.m.)
> 
> 
> Review request for mesos and Jie Yu.
> 
> 
> Bugs: MESOS-7973
> https://issues.apache.org/jira/browse/MESOS-7973
> 
> 
> Repository: mesos
> 
> 
> Description
> ---
> 
> NOP action is used as a filler for holes in the "fill" procedure and as
> the action in a response to a promise request for a truncated position.
> The tombstone flag is introduced so that replicas are able to
> distinguish the truncated action from a real NOP.
> 
> 
> Diffs
> -
> 
>   src/log/leveldb.cpp 5310a123b0fb25f240429722b676fe46174cb2ce 
>   src/log/replica.cpp 39f2879b2e37c1ca9a9f987ce0a3b83e8dbc9b43 
>   src/messages/log.proto ca740bd011147f8f48cc5dfcacefa5fdbd95ccd0 
>   src/tests/log_tests.cpp f9f9400c901152779ae0ebfe74cf8f7aac1d3396 
> 
> 
> Diff: https://reviews.apache.org/r/62285/diff/2/
> 
> 
> Testing
> ---
> 
> Added a test that verifies that a replica correctly handles the tombstone 
> NOP. Ran `make check`.
> 
> 
> Thanks,
> 
> Ilya Pronin
> 
>

Re: Review Request 62285: Added tombstone flag to NOP log action.

2017-09-24 Thread Jie Yu 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/62285/#review186083
---




src/log/leveldb.cpp
Lines 247 (patched)


I would combine this condition with the condition in `else if` above.



src/log/leveldb.cpp
Lines 364-366 (patched)


Can you explain this a bit more. When I see the code in `restore` above, I 
thought the invariant you want to maintain is: there is no tombstone entry in 
the replica's [begin,end]. Why the recovery code needs to see this position?



src/log/replica.cpp
Lines 735-736 (patched)


Ditto on combining considtions into a single `else if`


- Jie Yu


On Sept. 13, 2017, 4:40 p.m., Ilya Pronin wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/62285/
> ---
> 
> (Updated Sept. 13, 2017, 4:40 p.m.)
> 
> 
> Review request for mesos and Jie Yu.
> 
> 
> Bugs: MESOS-7973
> https://issues.apache.org/jira/browse/MESOS-7973
> 
> 
> Repository: mesos
> 
> 
> Description
> ---
> 
> NOP action is used as a filler for holes in the "fill" procedure and as
> the action in a response to a promise request for a truncated position.
> The tombstone flag is introduced so that replicas are able to
> distinguish the truncated action from a real NOP.
> 
> 
> Diffs
> -
> 
>   src/log/leveldb.cpp 5310a123b0fb25f240429722b676fe46174cb2ce 
>   src/log/replica.cpp 39f2879b2e37c1ca9a9f987ce0a3b83e8dbc9b43 
>   src/messages/log.proto ca740bd011147f8f48cc5dfcacefa5fdbd95ccd0 
>   src/tests/log_tests.cpp f9f9400c901152779ae0ebfe74cf8f7aac1d3396 
> 
> 
> Diff: https://reviews.apache.org/r/62285/diff/1/
> 
> 
> Testing
> ---
> 
> Added a test that verifies that a replica correctly handles the tombstone 
> NOP. Ran `make check`.
> 
> 
> Thanks,
> 
> Ilya Pronin
> 
>

Re: Review Request 62285: Added tombstone flag to NOP log action.

2017-09-25 Thread Ilya Pronin 


> On Sept. 25, 2017, 5:12 a.m., Jie Yu wrote:
> > src/log/leveldb.cpp
> > Lines 247 (patched)
> > 
> >
> > I would combine this condition with the condition in `else if` above.

Done!


> On Sept. 25, 2017, 5:12 a.m., Jie Yu wrote:
> > src/log/leveldb.cpp
> > Lines 364-366 (patched)
> > 
> >
> > Can you explain this a bit more. When I see the code in `restore` 
> > above, I thought the invariant you want to maintain is: there is no 
> > tombstone entry in the replica's [begin,end]. Why the recovery code needs 
> > to see this position?

Yes, there should not be tombstones in replica's `[begin, end]` and the replica 
should recover the same `begin` position as it had when it terminated. While 
the latter is not technically required, I think it is nice to follow the 
principle of least surprise (especially when it doesn't require much effort): 
the replica has already learned that `begin > 0`, why does it recover with 
`begin = 0`?

Currently, `LevelDBStorage` recovery code calculates replica's `begin` position 
like this (C++ish pseudocode):
```c++
begin = 0;
for (const auto& action : actions)
  if (action.type() == TRUNCATE)
begin = max(begin, action.truncate().to());
  else if (action.type() == NOP)
begin = max(begin, action.position() + 1);
```
If it doesn't see a tombstone or a `TRUNCATE` action, it will recover `begin = 
0`.

We can modify the recovery code to recover `begin` as the first position that 
we read from the disk. But we still need to persist the tombstone, because 
currently LevelDB truncations are best-effort.


> On Sept. 25, 2017, 5:12 a.m., Jie Yu wrote:
> > src/log/replica.cpp
> > Lines 735-736 (patched)
> > 
> >
> > Ditto on combining considtions into a single `else if`

Done!


- Ilya


---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/62285/#review186083
---


On Sept. 13, 2017, 5:40 p.m., Ilya Pronin wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/62285/
> ---
> 
> (Updated Sept. 13, 2017, 5:40 p.m.)
> 
> 
> Review request for mesos and Jie Yu.
> 
> 
> Bugs: MESOS-7973
> https://issues.apache.org/jira/browse/MESOS-7973
> 
> 
> Repository: mesos
> 
> 
> Description
> ---
> 
> NOP action is used as a filler for holes in the "fill" procedure and as
> the action in a response to a promise request for a truncated position.
> The tombstone flag is introduced so that replicas are able to
> distinguish the truncated action from a real NOP.
> 
> 
> Diffs
> -
> 
>   src/log/leveldb.cpp 5310a123b0fb25f240429722b676fe46174cb2ce 
>   src/log/replica.cpp 39f2879b2e37c1ca9a9f987ce0a3b83e8dbc9b43 
>   src/messages/log.proto ca740bd011147f8f48cc5dfcacefa5fdbd95ccd0 
>   src/tests/log_tests.cpp f9f9400c901152779ae0ebfe74cf8f7aac1d3396 
> 
> 
> Diff: https://reviews.apache.org/r/62285/diff/1/
> 
> 
> Testing
> ---
> 
> Added a test that verifies that a replica correctly handles the tombstone 
> NOP. Ran `make check`.
> 
> 
> Thanks,
> 
> Ilya Pronin
> 
>

Re: Review Request 62285: Added tombstone flag to NOP log action.

2017-09-25 Thread Ilya Pronin 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/62285/
---

(Updated Sept. 25, 2017, 2:05 p.m.)


Review request for mesos and Jie Yu.


Changes
---

Addressed review comments.


Bugs: MESOS-7973
https://issues.apache.org/jira/browse/MESOS-7973


Repository: mesos


Description
---

NOP action is used as a filler for holes in the "fill" procedure and as
the action in a response to a promise request for a truncated position.
The tombstone flag is introduced so that replicas are able to
distinguish the truncated action from a real NOP.


Diffs (updated)
-

  src/log/leveldb.cpp 5310a123b0fb25f240429722b676fe46174cb2ce 
  src/log/replica.cpp 39f2879b2e37c1ca9a9f987ce0a3b83e8dbc9b43 
  src/messages/log.proto ca740bd011147f8f48cc5dfcacefa5fdbd95ccd0 
  src/tests/log_tests.cpp f9f9400c901152779ae0ebfe74cf8f7aac1d3396 


Diff: https://reviews.apache.org/r/62285/diff/2/

Changes: https://reviews.apache.org/r/62285/diff/1-2/


Testing
---

Added a test that verifies that a replica correctly handles the tombstone NOP. 
Ran `make check`.


Thanks,

Ilya Pronin