log: Add real optimisic replication on log burst v1 APPLIED

Louis Solofrizzo: 1
 log: Add real optimisic replication on log burst

 5 files changed, 22 insertions(+), 5 deletions(-)

[PATCH] log: Add real optimisic replication on log burst Export this patch

This patch adds some code to try not to duplicate log sending when we
can avoid it. On log-write burst, the last known sent log is never
overrided by the node AE response, in order to avoid replay. When
heartbeating, the value _is_ overidded to allow replication on a
out-of-date node.

The main trade-off is that an out-of-date not will take longer to be
up-to-date again (hearbeat time, best case), but less data will be sent
on the wire.

Signed-off-by: Louis Solofrizzo <lsolofrizzo@scaleway.com>
---
 internal.h |  3 ++-
 log.c      | 14 ++++++++++++--
 node.h     |  1 +
 periodic.c |  2 +-
 raft.c     |  7 ++++++-
 5 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/internal.h b/internal.h
index d01147e..0f59c30 100644
--- a/internal.h
+++ b/internal.h
@@ -63,8 +63,9 @@ void libfloat_send_append_entries(libfloat_ctx_t *ctx, libfloat_node_t *node, bo
  * \brief Send AE requests to every node
  *
  * \param[in] ctx libfloat context
+ * \param[in] hearbeating Whether or not this is a hearbeat
  */
-void libfloat_send_append_entries_to_all(libfloat_ctx_t *ctx);
+void libfloat_send_append_entries_to_all(libfloat_ctx_t *ctx, bool hearbeating);
 
 /*!
  * \brief Start a snapshot
diff --git a/log.c b/log.c
index d877a54..06c9289 100644
--- a/log.c
+++ b/log.c
@@ -624,12 +624,22 @@ void libfloat_append_entries_response(libfloat_ctx_t *ctx, libfloat_rpc_append_e
 
     /* Set the next index to sent to the node */
     node->last_update = ctx->time(NULL);
-    if (node->next_log_to_send <= resp->current_index)
+
+    if (node->replicated_log < resp->current_index)
     {
-        node->next_log_to_send = resp->current_index + 1;
         node->replicated_log = resp->current_index;
     }
 
+    if (node->next_log_to_send <= resp->current_index && node->hearbeating)
+    {
+        node->next_log_to_send = resp->current_index + 1;
+    }
+
+    if (node->hearbeating)
+    {
+        node->hearbeating = false;
+    }
+
     if (ctx->persistent.term < resp->term)
     {
         libfloat_set_current_term(ctx, resp->term);
diff --git a/node.h b/node.h
index a91b4ef..f49ce9c 100644
--- a/node.h
+++ b/node.h
@@ -13,6 +13,7 @@ typedef struct {
     void                *udata;                 /*!< User data */
     time_t              last_update;            /*!< Time of the last AE response (If I am the leader) */
     int                 snapshot_count;         /*!< Count of the times we are supposed to send a snapshot */
+    bool                hearbeating;
 } libfloat_node_t;
 
 #endif /* LIBFLOAT_NODE_H */
diff --git a/periodic.c b/periodic.c
index aceecd2..94bf728 100644
--- a/periodic.c
+++ b/periodic.c
@@ -34,7 +34,7 @@ void libfloat_periodic(libfloat_ctx_t *ctx, uint32_t time)
             }
 
             /* Timeout has expired! Time to send some heartbeats or some entries */
-            libfloat_send_append_entries_to_all(ctx);
+            libfloat_send_append_entries_to_all(ctx, true);
             ctx->timeout_elapsed = 0;
         }
 
diff --git a/raft.c b/raft.c
index 1b651c4..bde3522 100644
--- a/raft.c
+++ b/raft.c
@@ -51,13 +51,18 @@ void libfloat_step_down(libfloat_ctx_t *ctx)
     ctx->state = RAFT_STATE_NONE;
 }
 
-void libfloat_send_append_entries_to_all(libfloat_ctx_t *ctx)
+void libfloat_send_append_entries_to_all(libfloat_ctx_t *ctx, bool heartbeat)
 {
     libfloat_node_t     *node;
 
     for_every_node(ctx, node, {
         if (node != ctx->me)
+        {
+            if (heartbeat)
+                node->hearbeating = true;
+
             libfloat_send_append_entries(ctx, node, false);
+        }
     });
 }
 
-- 
2.33.1

Patrik Cyvoct <patrik@ptrk.io>

9 months ago

LG