12:44 p.m.
Gitweb:
http://git.fedorahosted.org/git/cluster.git?p=cluster.git;a=commitdiff;h=...
Commit: e2937eb33f224f86904fead08499a6178868ca6a
Parent: 6707ff0f2a248dd0a05e13d9f563806cd93c6cb4
Author: Lon Hohberger <lhh(a)redhat.com>
AuthorDate: Fri May 6 10:14:04 2011 -0400
Committer: Lon Hohberger <lhh(a)redhat.com>
CommitterDate: Thu Jun 23 13:42:41 2011 -0400
qdiskd: Make multipath issues go away
Qdiskd hsitorically has required significant tuning to work around
delays which occur during multipath failover, overloaded I/O, and LUN
trespasses in both device-mapper-multipath and EMC PowerPath
environments.
This patch goes a very long way towards eliminating false evictions
when these conditions occur by making qdiskd whine to the other
cluster members when it detects hung system calls. When a cluster
member whines, it indicates the source of the problem (which system
call is hung), and the act of receiving a whine from a host indicates
that qdiskd is operational, but that I/O is hung. Hung I/O is different
from losing storage entirely (where you get I/O errors).
Possible problems:
- Receive queue getting very full, causing messages to become blocked on
a node where I/O is hung. 1) that would take a very long time, and 2)
node should get evicted at that point anyway.
Signed-off-by: Lon Hohberger <lhh(a)redhat.com>
---
cman/qdisk/Makefile | 2 +-
cman/qdisk/disk.h | 6 ++++++
cman/qdisk/iostate.c | 16 +++++++++++++---
cman/qdisk/iostate.h | 4 +++-
cman/qdisk/main.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
5 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/cman/qdisk/Makefile b/cman/qdisk/Makefile
index 68e20cd..e3bb5f7 100644
--- a/cman/qdisk/Makefile
+++ b/cman/qdisk/Makefile
@@ -40,7 +40,7 @@ ${TARGET1}: ${SHAREDOBJS} ${OBJS1}
$(CC) -o $@ $^ $(EXTRA_LDFLAGS) $(LDFLAGS)
${TARGET2}: ${SHAREDOBJS} ${OBJS2}
- $(CC) -o $@ $^ $(LDFLAGS)
+ $(CC) -o $@ $^ $(EXTRA_LDFLAGS) $(LDFLAGS)
depends:
$(MAKE) -C ../lib all
diff --git a/cman/qdisk/disk.h b/cman/qdisk/disk.h
index 93d15fe..fd80fa6 100644
--- a/cman/qdisk/disk.h
+++ b/cman/qdisk/disk.h
@@ -273,6 +273,12 @@ typedef struct {
status_block_t ni_status;
} node_info_t;
+typedef struct {
+ qd_ctx *ctx;
+ node_info_t *ni;
+ size_t ni_len;
+} qd_priv_t;
+
int qd_write_status(qd_ctx *ctx, int nid, disk_node_state_t state,
disk_msg_t *msg, memb_mask_t mask, memb_mask_t master);
int qd_init(qd_ctx *ctx, cman_handle_t ch_admin,
diff --git a/cman/qdisk/iostate.c b/cman/qdisk/iostate.c
index 0199da4..06c6831 100644
--- a/cman/qdisk/iostate.c
+++ b/cman/qdisk/iostate.c
@@ -1,9 +1,12 @@
#include <pthread.h>
+#include <libcman.h>
#include <iostate.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <liblogthread.h>
+#include <stdint.h>
+#include "platform.h"
#include "iostate.h"
static iostate_t main_state = 0;
@@ -26,7 +29,7 @@ static struct state_table io_state_table[] = {
{ STATE_LSEEK, "seek" },
{ -1, NULL } };
-static const char *
+const char *
state_to_string(iostate_t state)
{
static const char *ret = "unknown";
@@ -65,6 +68,8 @@ io_nanny_thread(void *arg)
iostate_t last_main_state = 0, current_main_state = 0;
int last_main_incarnation = 0, current_main_incarnation = 0;
int logged_incarnation = 0;
+ cman_handle_t ch = (cman_handle_t)arg;
+ int32_t whine_state;
/* Start with wherever we're at now */
pthread_mutex_lock(&state_mutex);
@@ -96,6 +101,11 @@ io_nanny_thread(void *arg)
continue;
}
+ /* Whine on CMAN api */
+ whine_state = (int32_t)current_main_state;
+ swab32(whine_state);
+ cman_send_data(ch, &whine_state, sizeof(int32_t), 0, 178, 0);
+
/* Don't log things twice */
if (logged_incarnation == current_main_incarnation)
continue;
@@ -114,7 +124,7 @@ io_nanny_thread(void *arg)
int
-io_nanny_start(int timeout)
+io_nanny_start(cman_handle_t ch, int timeout)
{
int ret;
@@ -124,7 +134,7 @@ io_nanny_start(int timeout)
qdisk_timeout = timeout;
thread_active = 1;
- ret = pthread_create(&io_nanny_tid, NULL, io_nanny_thread, NULL);
+ ret = pthread_create(&io_nanny_tid, NULL, io_nanny_thread, ch);
pthread_mutex_unlock(&state_mutex);
return ret;
diff --git a/cman/qdisk/iostate.h b/cman/qdisk/iostate.h
index 7dd7bf6..a65b1d4 100644
--- a/cman/qdisk/iostate.h
+++ b/cman/qdisk/iostate.h
@@ -11,7 +11,9 @@ typedef enum {
void io_state(iostate_t state);
-int io_nanny_start(int timeout);
+int io_nanny_start(cman_handle_t ch, int timeout);
int io_nanny_stop(void);
+const char * state_to_string(iostate_t state);
+
#endif
diff --git a/cman/qdisk/main.c b/cman/qdisk/main.c
index 9262af2..c1598fa 100644
--- a/cman/qdisk/main.c
+++ b/cman/qdisk/main.c
@@ -904,7 +904,8 @@ cman_wait(cman_handle_t ch, struct timeval *_tv)
static void
process_cman_event(cman_handle_t handle, void *private, int reason, int arg)
{
- qd_ctx *ctx = (qd_ctx *)private;
+ qd_priv_t *qp = (qd_priv_t *)private;
+ qd_ctx *ctx = qp->ctx;
switch(reason) {
case CMAN_REASON_PORTOPENED:
@@ -1915,6 +1916,33 @@ check_stop_cman(qd_ctx *ctx)
do { static int _logged=0; if (!_logged) { _logged=1; logt_print(level, fmt, ##args); } }
while(0)
+static void
+qdisk_whine(cman_handle_t h, void *privdata, char *buf, int len,
+ uint8_t port, int nodeid)
+{
+ int32_t dstate;
+ qd_priv_t *qp = (qd_priv_t *)privdata;
+ node_info_t *ni = qp->ni;
+
+ if (len != sizeof(dstate)) {
+ return;
+ }
+
+ dstate = *((int32_t*)buf);
+
+ if (nodeid == (qp->ctx->qc_my_id))
+ return;
+
+ swab32(dstate);
+
+ if (dstate) {
+ logt_print(LOG_NOTICE, "qdiskd on node %d reports hung %s()\n", nodeid,
+ state_to_string(dstate));
+ ni[nodeid-1].ni_misses = 0;
+ }
+}
+
+
int
main(int argc, char **argv)
{
@@ -1928,6 +1956,7 @@ main(int argc, char **argv)
char device[128];
pid_t pid;
quorum_header_t qh;
+ qd_priv_t qp;
if (check_process_running(argv[0], &pid) && pid !=getpid()) {
printf("QDisk services already running\n");
@@ -1990,13 +2019,23 @@ main(int argc, char **argv)
/* For cman notifications we need two sockets - one for events,
one for config change callbacks */
- ch_user = cman_init(&ctx);
+ qp.ctx = &ctx;
+ qp.ni = &ni[0];
+ qp.ni_len = MAX_NODES_DISK;
+
+ ch_user = cman_init(&qp);
if (cman_start_notification(ch_user, process_cman_event) != 0) {
logt_print(LOG_CRIT, "Could not register with CMAN: %s\n",
strerror(errno));
goto out;
}
+ if (cman_start_recv_data(ch_user, qdisk_whine, 178) != 0) {
+ logt_print(LOG_CRIT, "Could not register with CMAN: %s\n",
+ strerror(errno));
+ goto out;
+ }
+
memset(&me, 0, sizeof(me));
if (cman_get_node(ch_admin, CMAN_NODEID_US, &me) < 0) {
logt_print(LOG_CRIT, "Could not determine local node ID: %s\n",
@@ -2084,7 +2123,7 @@ main(int argc, char **argv)
/* This registers the quorum device */
register_device(&ctx);
- io_nanny_start(ctx.qc_tko * ctx.qc_interval);
+ io_nanny_start(ch_user, ctx.qc_tko * ctx.qc_interval);
if (quorum_loop(&ctx, ni, MAX_NODES_DISK) == 0) {
/* Only clean up if we're exiting w/o error) */