Function clusterWriteHandler

app/redis-6.2.6/src/cluster.c:2256–2270

Send data. This is handled using a trivial send buffer that gets * consumed by write(). We don't try to optimize this for speed too much * as this is a very low traffic channel. */

 * consumed by write(). We don't try to optimize this for speed too much
 * as this is a very low traffic channel. */
void clusterWriteHandler(connection *conn) {
    clusterLink *link = connGetPrivateData(conn);
    ssize_t nwritten;

    nwritten = connWrite(conn, link->sndbuf, sdslen(link->sndbuf));
    if (nwritten <= 0) {
        serverLog(LL_DEBUG,"I/O error writing to node link: %s",
            (nwritten == -1) ? connGetLastError(conn) : "short write");
        handleLinkIOError(link);
        return;
    }
    sdsrange(link->sndbuf,nwritten,-1);
    if (sdslen(link->sndbuf) == 0)
        connSetWriteHandler(link->conn, NULL);
}

/* A connect handler that gets called when a connection to another node
 * gets established.