upstream/redis
1
0
Fork 0
mirror of https://github.com/redis/redis.git synced 2026-02-03 20:39:54 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

Fix Fully drain cluster link send buffer to prevent OOM (#14310)

Browse source 
Under a high rate of PUBLISH commands, a Redis cluster node needs to broadcast these messages to other nodes. The `clusterWriteHandler`, which handles writing to the cluster link, previously limited the total bytes written per event loop cycle.

When the message ingress rate is higher than the egress rate allowed by this limit, the link's send queue (`send_msg_queue`) grows continuously. This unbounded growth leads to excessive memory consumption and can ultimately cause an Out-Of-Memory (OOM) error, crashing the node.

This commit removes the write limit in `clusterWriteHandler`. By doing so, the handler will now attempt to drain the entire send queue in each invocation. This prevents the buffer from bloating and ensures the stability of the cluster under heavy broadcast loads.
This commit is contained in:
yang.l 2025-08-27 16:13:52 +08:00
parent 35aacdf80a
commit 64a77caa11
1 changed files with 1 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
src/cluster_legacy.c
View file

@ -3320,9 +3320,8 @@ void handleLinkIOError(clusterLink *link) {
void clusterWriteHandler(connection *conn) {
clusterLink *link = connGetPrivateData(conn);
ssize_t nwritten;
size_t totwritten = 0;
while (totwritten < NET_MAX_WRITES_PER_EVENT && listLength(link->send_msg_queue) > 0) {
while (listLength(link->send_msg_queue) > 0) {
listNode *head = listFirst(link->send_msg_queue);
clusterMsgSendBlock *msgblock = (clusterMsgSendBlock*)head->value;
clusterMsg *msg = getMessageFromSendBlock(msgblock);
@ -3350,8 +3349,6 @@ void clusterWriteHandler(connection *conn) {
listDelNode(link->send_msg_queue, head);
server.stat_cluster_links_memory -= sizeof(listNode);
link->send_msg_queue_mem -= sizeof(listNode) + blocklen;
totwritten += nwritten;
}
if (listLength(link->send_msg_queue) == 0)