On 10/27/2011 07:51 PM, Yunkai Zhang wrote:
> On Fri, Oct 28, 2011 at 9:23 AM, Angus Salkeld <asalkeld@xxxxxxxxxx> wrote:
>> Thanks for the patch! Some comments inline.
>>
>> -Angus
>>
>> On Fri, Oct 28, 2011 at 12:22:13AM +0800, Yunkai Zhang wrote:
>>> We found that sheepdog will receive more than one confchg msg when
>>> network partition occur. For example, suppose the cluster has 4
>>> nodes: N1, N2, N3, N4, and they form a single-ring initially. After a
>>> while, network partition occur, the single-ring divide into two
>>> sub-ring: ring(N1, N2, N3) and ring(N4). The sheepdog in the ring(N4)
>>> will receive the following confchg messages in turn:
>>> Memb: N2,N3,N4 Left:N1 Joined:null
>>> memb: N3,N4 Left:N2 Joined:null
>>> memb: N4 Left:N3 Joined:null
>>>
>>> This patch will fixed this bug, and the client will only receive one
>>> confchg event in this case:
>>> memb: N4 Left:N2,N3,N4 Joined:null
>>>
>>> Signed-off-by: Yunkai Zhang <qiushu.zyk@xxxxxxxxxx>
>>> ---
>>> configure.ac | 2 +-
>>> include/corosync/cpg.h | 1 +
>>> services/cpg.c | 97 +++++++++++++++++++++++++++++++++++++++++-------
>>> 3 files changed, 85 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/configure.ac b/configure.ac
>>> index 563f799..aaed478 100644
>>> --- a/configure.ac
>>> +++ b/configure.ac
>>> @@ -88,7 +88,7 @@ AC_HEADER_SYS_WAIT
>>> AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netdb.h netinet/in.h stdint.h \
>>> stdlib.h string.h sys/ioctl.h sys/param.h sys/socket.h \
>>> sys/time.h syslog.h unistd.h sys/types.h getopt.h malloc.h \
>>> - sys/sockio.h utmpx.h])
>>> + sys/sockio.h utmpx.h search.h])
>>
>> Why this? it's not included anywhere in corosync.
>>
>
> Sorry, I forgot to clear it.
>
> I wrote the first version of this patch base on v1.4.1 which not
> provide libqb and I used hash table api comes from search.h instead of
> qbmap.h.
>
>>>
>>> # Checks for typedefs, structures, and compiler characteristics.
>>> AC_C_CONST
>>> diff --git a/include/corosync/cpg.h b/include/corosync/cpg.h
>>> index f7956fa..9861c5a 100644
>>> --- a/include/corosync/cpg.h
>>> +++ b/include/corosync/cpg.h
>>> @@ -95,6 +95,7 @@ struct cpg_name {
>>> };
>>>
>>> #define CPG_MEMBERS_MAX 128
>>> +#define CPG_GROUPS_MAX 64
>>
Go with 8192 groups - we have some use cases where many groups are
needed - memory consumption shouldn't be much of an issue.
>> I think this is ok, though not 100% sure.
>>
>>>
>>> struct cpg_iteration_description_t {
>>> struct cpg_name group;
>>> diff --git a/services/cpg.c b/services/cpg.c
>>> index caec097..dc72c84 100644
>>> --- a/services/cpg.c
>>> +++ b/services/cpg.c
>>> @@ -55,6 +55,7 @@
>>> #include <netinet/in.h>
>>> #include <arpa/inet.h>
>>> #include <sys/mman.h>
>>> +#include <qb/qbmap.h>
>>>
>>> #include <corosync/corotypes.h>
>>> #include <qb/qbipc_common.h>
>>> @@ -705,7 +706,6 @@ static int notify_lib_joinlist(
>>> for (iter = cpg_pd_list_head.next; iter != &cpg_pd_list_head; iter = iter->next) {
>>> struct cpg_pd *cpd = list_entry (iter, struct cpg_pd, list);
>>> if (mar_name_compare (&cpd->group_name, group_name) == 0) {
>>> - assert (left_list_entries <= 1);
>>> assert (joined_list_entries <= 1);
>>> if (joined_list_entries) {
>>> if (joined_list[0].pid == cpd->pid &&
>>> @@ -798,8 +798,18 @@ static void downlist_master_choose_and_send (void)
>>> {
>>> struct downlist_msg *stored_msg;
>>> struct list_head *iter;
>>> - mar_cpg_address_t left_list;
>>> - int i;
>>> + struct process_info *left_pi;
>>> + struct qb_map_t *group_htab;
>>> + struct cpg_name cpg_group;
>>> + mar_cpg_name_t group;
>>> + struct confchg_data{
>>> + struct cpg_name cpg_group;
>>> + mar_cpg_address_t left_list[CPG_MEMBERS_MAX];
>>> + int left_list_entries;
>>> + struct list_head list;
>>> + } *pcd;
>>> + DECLARE_LIST_INIT(confchg_data_list_head);
>>> + int i, size;
>>
>> Why the list? You could use qb_skiplist_create() and use the
>> iterator.
>>
>> miter = qb_map_iter_create(group_map);
>> while ((p = qb_map_iter_next(miter, (void**)&pcd))) {
>> ...
>> }
>>
>> Though using libqb here is going to make it impossible to cherry-pick
>> the patch into the flatiron branch (Steven/Honzaf would this be needed
>> there?).
>>
>
agree use skiplist
> I worry about the same thing for my project using v1.4.1 now.
>
> Does Steven/Honza give some advice?
>
For an invasive patch like this, what would be ideal is a master version
and a separate patch for flatiron. Typically the branch maintainer
(Honza) would cherry-pick simple bug fixes, but this is major rework and
warrants a separate patch. It must go into master prior to flatiron to
avoid behavioural regressions when moving forward in versions.
>>>
>>> downlist_state = CPG_DOWNLIST_APPLYING;
>>>
>>> @@ -810,27 +820,86 @@ static void downlist_master_choose_and_send (void)
>>> }
>>> downlist_log("chosen downlist", stored_msg);
>>>
>>> - /* send events */
>>> + group_htab = qb_hashtable_create(CPG_GROUPS_MAX);
>>> +
>>> + /*
>>> + * only the cpg groups included in left nodes should receive
>>> + * confchg event, so we will collect these cpg groups and
>>> + * relative left_lists here
>>> + */
>>> for (iter = process_info_list_head.next; iter != &process_info_list_head; ) {
>>> struct process_info *pi = list_entry(iter, struct process_info, list);
>>> iter = iter->next;
>>>
>>> + left_pi = NULL;
>>> for (i = 0; i < stored_msg->left_nodes; i++) {
>>> +
>>> if (pi->nodeid == stored_msg->nodeids[i]) {
>>> - left_list.nodeid = pi->nodeid;
>>> - left_list.pid = pi->pid;
>>> - left_list.reason = CONFCHG_CPG_REASON_NODEDOWN;
>>> -
>>> - notify_lib_joinlist(&pi->group, NULL,
>>> - 0, NULL,
>>> - 1, &left_list,
>>> - MESSAGE_RES_CPG_CONFCHG_CALLBACK);
>>> - list_del (&pi->list);
>>> - free (pi);
>>> + left_pi = pi;
>>> break;
>>> }
>>> }
>>> +
>>> + if (left_pi) {
>>> + marshall_from_mar_cpg_name_t(&cpg_group, &left_pi->group);
>>> + log_printf (LOG_DEBUG, "cpg group name:%s", cpg_group.value);
>>> + cpg_group.value[cpg_group.length] = 0;
>>> +
>>> + pcd = (struct confchg_data *)qb_map_get(group_htab,
>>> + cpg_group.value);
>>> + if (pcd != NULL) {
>>> + size = pcd->left_list_entries;
>>> + pcd->left_list[size].nodeid = left_pi->nodeid;
>>> + pcd->left_list[size].pid = left_pi->pid;
>>> + pcd->left_list[size].reason = CONFCHG_CPG_REASON_NODEDOWN;
>>> + pcd->left_list_entries++;
>>> + }else {
>>> + pcd = (struct confchg_data *)malloc(sizeof(struct confchg_data));
>>> + memset(pcd, 0, sizeof(struct confchg_data));
>>> +
>>> + memcpy(&pcd->cpg_group, &cpg_group, sizeof(struct cpg_name));
>>> + pcd->left_list[0].nodeid = left_pi->nodeid;
>>> + pcd->left_list[0].pid = left_pi->pid;
>>> + pcd->left_list[0].reason = CONFCHG_CPG_REASON_NODEDOWN;
>>> + pcd->left_list_entries = 1;
>>> +
>>> + qb_map_put(group_htab, pcd->cpg_group.value, pcd);
>>> +
>>> + list_init(&pcd->list);
>>> + list_add(&pcd->list, &confchg_data_list_head);
>>> + }
>>
>> This could be a bit simplified:
>>
>> pcd = (struct confchg_data *)qb_map_get(group_map,
>> cpg_group.value);
>> if (pcd == NULL) {
>> pcd = (struct confchg_data *)calloc(1, sizeof(struct confchg_data));
>> memcpy(&pcd->cpg_group, &cpg_group, sizeof(struct cpg_name));
>> qb_map_put(group_map, pcd->cpg_group.value, pcd);
>> }
>> size = pcd->left_list_entries;
>> pcd->left_list[size].nodeid = left_pi->nodeid;
>> pcd->left_list[size].pid = left_pi->pid;
>> pcd->left_list[size].reason = CONFCHG_CPG_REASON_NODEDOWN;
>> pcd->left_list_entries++;
>> list_del (&left_pi->list);
>> free (left_pi);
>
> Thanks, It looks cool!
>
>>
>>> +
>>> + list_del (&left_pi->list);
>>> + free (left_pi);
>>> + }
>>> + }
>>> +
>>> + /* send only one confchg event per cpg group */
>>> + for (iter = confchg_data_list_head.next; iter != &confchg_data_list_head; ) {
>>> + pcd = list_entry(iter, struct confchg_data, list);
>>> + iter = iter->next;
>>> +
>>> + marshall_to_mar_cpg_name_t(&group, &pcd->cpg_group);
>>> +
>>> + log_printf (LOG_DEBUG, "left_list_entries:%d", pcd->left_list_entries);
>>> + for (i=0; i<pcd->left_list_entries; i++) {
>>> + log_printf (LOG_DEBUG, "left_list[%d] group:%d, ip:%s, pid:%d",
>>> + i, pcd->cpg_group.value,
>>> + (char*)api->totem_ifaces_print(pcd->left_list[i].nodeid),
>>> + pcd->left_list[i].pid);
>>> + }
>>> +
>>> + /* send confchg event */
>>> + notify_lib_joinlist(&group, NULL,
>>> + 0, NULL,
>>> + pcd->left_list_entries,
>>> + pcd->left_list,
>>> + MESSAGE_RES_CPG_CONFCHG_CALLBACK);
>>> +
>>> + free(pcd);
>>> }
>>> +
>>> + qb_map_destroy(group_htab);
>>> }
>>>
>>> static void downlist_messages_delete (void)
>>> --
>>> 1.7.6.4
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>> http://lists.corosync.org/mailman/listinfo/discuss
>>
>
>
>
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