- 25 Oct, 2022 2 commits
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Ozan Tezcan authored
This PR refactors code regarding `term` handling inside `raft_recv_appendentries()` and `raft_recv_snapshot()` without introducing any logic changes. - Deleted `raft_receive_term()` function: This function sets the node as follower in certain cases. Although, it misses the pre-candidate state. We already set the node as follower inside `raft_accept_leader()`. (With the correct check that also handles pre-candidate state). - Moved `raft_reset_transfer_leader()` into `raft_accept_leader()`. Leader transfer is completed when we accept a leader. So, it makes sense to move it into `raft_accept_leader()`. - Added some tests to verify node becomes follower even on a pre-candidate state when a request is received with same or higher term.
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Ozan Tezcan authored
Refactored raft_recv_appendentries() just to simplify the flow. This PR should not introduce any behavioral change. Only exception is previously, some tests were manually creating an append request with prev_log_idx:0 and prev_log_term:1. This is not possible and it cannot happen without manually creating append requests. Term of the entry at index 0 cannot be 1. (it is zero by definition). Fixed these tests as part of this PR.
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- 03 Oct, 2022 1 commit
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Hanna Fadida authored
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- 12 Sep, 2022 1 commit
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Ozan Tezcan authored
A node can receive responses from followers who are not aware of they have been removed from the cluster configuration. In this case, recv_ family functions can be called without a node structure. We should ignore these messages. We should also ignore snapshot and appendentries responses if we are not leader anymore. Returning an error code for this case does not make sense because application cannot do anything but ignore the error code. This PR changes return value to zero for these cases.
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- 05 Sep, 2022 1 commit
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Ozan Tezcan authored
Revert change for sending timeout message. Introduced by https://github.com/RedisLabs/raft/pull/127. This PR deleted the check to prevent sending duplicate timeout messages.
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- 04 Sep, 2022 1 commit
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Ozan Tezcan authored
Propagate error codes from persist_metadata() callback
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- 30 Aug, 2022 1 commit
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Ozan Tezcan authored
Refactor debug logging and change log callback e.g: 19 --> 13, sent snapshot_resp id:27712, t:24, s:1, o:4096, lc:0 14 --> 17, sent requestvote_req pv:1, t:25, ci:14, lli:6848, llt:23 14 <-- 17, recv requestvote_resp pv:1, t:25, rt:24, vg:0 Breaking changes: raft_log_f() callback will not pass node_id_t anymore. Sender and receiver will be part of the log line as you can see above.
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- 29 Aug, 2022 2 commits
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Ozan Tezcan authored
Simplied pop callback. Previously, libraft was passing a callback(raft_entry_notify_f) to the pop callback. The application was supposed to call that callback for each removed entry. Libraft can loop over the entries and call the required functions itself. So, we can delete raft_entry_notify_f from the pop callback just to simplify API. In addition to that, this PR removes raft_pop_entry() function which doesn't have a use-case, as far as I can see. We can use raft_delete_entry_from_idx(me, raft_get_current_idx()) instead if required.
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Ozan Tezcan authored
Add raft_get_last_applied_term()
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- 25 Aug, 2022 1 commit
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Ozan Tezcan authored
Configuration changes are special in Raft. They take effect whenever the related log entries are appended. On a restart, we should go over the log entries and rebuild the configuration. Adding raft_restore_log() function for this purpose. Overall, on a restart, application should do: Load the snapshot and call raft_restore_snapshot() Load the log entries and call raft_restore_log() Read the metadata file and call raft_restore_metadata().
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- 23 Aug, 2022 1 commit
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Ozan Tezcan authored
Combine raft_persist_vote_f and raft_persist_term_f into a single callback: raft_persist_metadata_f. Users should persist vote and term into a single metadata file. After a restart, application should call raft_restore_metadata() to restore vote and term
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- 08 Aug, 2022 1 commit
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Ozan Tezcan authored
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- 07 Jul, 2022 1 commit
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Ozan Tezcan authored
Throttle operations early not to block server Introduced throttling in #106. If execution of operations take as much as request-timeout, it means this server will not generate responses on time for the existing requests. This is causing extra elections. I've changed deadline as 'now + request_timeout / 2', giving server some room for other operations and enough time to send responses.
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- 30 Jun, 2022 1 commit
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Ozan Tezcan authored
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- 19 Jun, 2022 1 commit
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Ozan Tezcan authored
Throttle operations if it takes longer than request timeout
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- 19 May, 2022 1 commit
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Ozan Tezcan authored
Simplify read request processing
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- 15 May, 2022 1 commit
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Ozan Tezcan authored
Fix next_idx and next_msgid usages
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- 02 May, 2022 1 commit
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Ozan Tezcan authored
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- 26 Apr, 2022 1 commit
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Ozan Tezcan authored
Add raft_config() function for configuration
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- 06 Apr, 2022 1 commit
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Ozan Tezcan authored
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- 04 Apr, 2022 1 commit
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Ozan Tezcan authored
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- 03 Apr, 2022 1 commit
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Ozan Tezcan authored
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- 30 Mar, 2022 2 commits
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Ozan Tezcan authored
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Ozan Tezcan authored
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- 24 Mar, 2022 1 commit
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Ozan Tezcan authored
Delete private typedefs, use namespace raft_ for exported symbols
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- 21 Mar, 2022 1 commit
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Ozan Tezcan authored
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- 07 Feb, 2022 1 commit
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Ozan Tezcan authored
Add support for async disk flush, backpressure and batching
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- 03 Nov, 2021 1 commit
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Shaya Potter authored
this is to avoid sending duplicate entries each time raft_send_appendentries is called, just because they haven't been acked yet. it will still be reset backwards upon the leader receiving a raft_recv_appendentries_response() with a failure mode + a test for next_idx on append entry, which changes a number of tests which checked for this in order to do this, I had to modify the existing mock callback to return 0 instead of 1. this needs to be verified + fixes for raft tests that this change exposed 1) when we issues a sequence of entries, each was given an increasing term, so had entries whose term was higher than leaders term so had to fix that 2) by setting the term of appendentries_repsonse to not be equal to leaders term (because of fix above), we now fail on receiving them do all that by not allowing raft_append_entry to append an entry that break raft semantics (i.e. term of entry > log term), but this breaks many tests that don't set term, so set them
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- 07 Oct, 2021 1 commit
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Shaya Potter authored
this started off as a small tweak and grew a bit 1) new callback for transfer leader result, along with its own enum of states 2) change/remove raft_reset_transfer_leader() calls only call in places where there's a new leader or timeout (i.e. failed to transfer within period). so, we only reset in 3 places 1) recv_appendentries 2) raft_periodic (timeout) 3) raft_become_leader 2a) raft_become_leader also got refactored a little to only issue the normal cb.notify_state_event() callback after it has set its state to be leader (as before, it could fail after the callback was issued) 2b) in raft_periodic the raft_reset_transfer_leader() is pulled out the "if LEADER" block, as will lose leader when a vote is issued to it, we still want it to timeout if leadership isn't gained 3) raft_reset_transfer_leader() does the logic for determining success/failure now, but becaue timeout is its own result which can't be determined by just looking at leader/desired, add a new flag to it to note timeout state 4) leader stickiness in requestvote is only tested for prevote (as in a timeout now case, we want to drop the timeout now flag after prevotes are sent). The idea is that we will only get to actual election if prevote passes. 4) a bunch of new tests * fix issue with timeout flag to reset_transfer_leader also fix test to catch the original error * libraft/redisraft changes needed for e2e leader transfer * make leader stickiness only for prevote
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- 23 Sep, 2021 2 commits
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Shaya Potter authored
this is the small modifications needed for raftlib to support timeout now rpc 1) add a flag to requestvote type to tell other nodes its overriding normal chec 2) new send_timeoutnow callback to send a timeout now rpc at right time 3) call said callback is we've marked the node as timeout now and in raft_appendentries_response raft_get_current_idx(me_) == r->current_idx (i.e. response says the node's idx is up to date with leader) 4) add helper functions to set/get/reset timeout flag on node structs for targeted node. how it would be used by client 1) client of libraft will call raft_transfer_leader(raft_server_t* me_, raft_node_id_t node_id) to target the node they want to transfer to. 2) client of libraft will provide the send_timeoutnow() callback for the actual sending of the rpc 3) client of libraft will modify their existing notify_state_event() callback to observe the result of the timeout now operation. if it receives a RAFT_STATE_LEADERSHIP_TRANSFER_FAILED, then the transfer failed if it received a RAFT_STATE_FOLLOWER, then it inspects for the actual leader to see if its the expected one and can return that it was transferred to expected node or not if it received a RAFT_STATE_CANDIDATE, then the transfer also failed, as the targeted node sent a request vote which removed leadership, but wasn't able to win the election. With PreVote, this latter case should be very rare.
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Ozan Tezcan authored
Define separate callback function for node id retrieval
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- 15 Sep, 2021 1 commit
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Ozan Tezcan authored
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- 14 Sep, 2021 2 commits
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Ozan Tezcan authored
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Ozan Tezcan authored
* prevote implementation
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- 09 Sep, 2021 1 commit
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Ozan Tezcan authored
Unknown node handling
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- 01 Sep, 2021 1 commit
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Shaya Potter authored
the problem we have is that 2 appendentries can be in process in parallel Howver, the response handler doesn't expect this, it will reset the next_idx in both, but currently resets next_idx based on next_idx's value, not the old value that was the basis of prev_log_idx. Solution: return prev_log_idx in the response Problem with solution: prev_log_idx is not always based on next_idx from node, but can be based on a snapshot idx if it no longer exists. I haven't coded this yet, but perhaps can determine if the prev_log_idx that is returned is the snapshot_idx and if so, then dont increment by 1. Its possible we could pass even another flag into the appendentries struct to say if its a snapshot, but that's ugly. In addition, we increment msg_id on each appendentries so that if a response comes back out of order and we have already accepted the later response, we just ignore this response. In addition, on appendentry response, even if the appendentry wasn't a success, as long as its the same term as us (i.e. we are still the leader) then for leader/quorum purposes, that is sufficient, so move up set_last_ack to right after term test.
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- 18 Aug, 2021 1 commit
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Ozan Tezcan authored
Implemented check-quorum
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- 11 Aug, 2021 1 commit
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Ozan Tezcan authored
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- 06 Aug, 2021 1 commit
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Ozan Tezcan authored
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- 02 Aug, 2021 1 commit
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Shaya Potter authored
major bug in terms of election as term wasn't being increased in cases of partioned network where a demote was received but not applied. + adds an assert to the existing test of promotion to leader if only voter to ensure term is incremented as fixed by this PR
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