/*
* iterate backends and update
* - healthy bitmap
* - number of healthy backends
* - total_weight
* - last change time of the VCL_BACKEND
*
* must be called under the vdir lock (read or write).
*
* A write lock is required if consistency between the individual attributes is
* a must, e.g. when total_weight is required to be the exact sum of the weights
*
* The read lock is safe because add_backend expands the healthy bitmap and all
* other members are atomic and may be used if consistency is not required.
*/
void
vdir_update_health(VRT_CTX, struct vdir *vd)
{
VCL_TIME c, changed = 0;
VCL_BOOL h;
VCL_BACKEND be;
unsigned u, nh = 0;
double tw = 0.0;
struct vbitmap *healthy;
CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
healthy = vd->healthy;
for (u = 0; u < vd->n_backend; u++) {
be = vd->backend[u];
CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
c = 0;
h = VRT_Healthy(ctx, vd->backend[u], &c);
if (h) {
nh++;
tw += vd->weight[u];
}
if (c > changed)
changed = c;
if (h != vbit_test(healthy, u)) {
if (h)
vbit_set(healthy, u);
else
vbit_clr(healthy, u);
}
}
VRT_SetChanged(vd->dir, changed);
vd->total_weight = tw;
vd->n_healthy = nh;
}
VCL_BOOL
vdir_any_healthy(VRT_CTX, struct vdir *vd, VCL_TIME *changed)
{
unsigned retval = 0;
VCL_BACKEND be;
unsigned u;
vtim_real c;
CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
vdir_rdlock(vd);
if (changed != NULL)
*changed = 0;
for (u = 0; u < vd->n_backend; u++) {
be = vd->backend[u];
CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
retval = VRT_Healthy(ctx, be, &c);
if (changed != NULL && c > *changed)
*changed = c;
if (retval)
break;
}
vdir_unlock(vd);
return (retval);
}
/* basically same as vdir_any_healthy
* - XXX we should embed a vdir
* - XXX should we return the health state of the actual backend
* for healthy=IGNORE ?
*/
VCL_BOOL
sharddir_any_healthy(VRT_CTX, struct sharddir *shardd, VCL_TIME *changed)
{
unsigned retval = 0;
VCL_BACKEND be;
unsigned u;
vtim_real c;
CHECK_OBJ_NOTNULL(shardd, SHARDDIR_MAGIC);
sharddir_rdlock(shardd);
if (changed != NULL)
*changed = 0;
for (u = 0; u < shardd->n_backend; u++) {
be = shardd->backend[u].backend;
CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
retval = VRT_Healthy(ctx, be, &c);
if (changed != NULL && c > *changed)
*changed = c;
if (retval)
break;
}
sharddir_unlock(shardd);
return (retval);
}
static int
shard_next(struct shard_state *state, VCL_INT skip, VCL_BOOL healthy)
{
int c, chosen = -1;
uint32_t ringsz;
VCL_BACKEND be;
vtim_real changed;
struct shard_be_info *sbe;
AN(state);
assert(state->idx >= 0);
CHECK_OBJ_NOTNULL(state->shardd, SHARDDIR_MAGIC);
if (state->pickcount >= state->shardd->n_backend)
return -1;
ringsz = state->shardd->n_backend * state->shardd->replicas;
while (state->pickcount < state->shardd->n_backend && skip >= 0) {
c = state->shardd->hashcircle[state->idx].host;
if (!vbit_test(state->picklist, c)) {
vbit_set(state->picklist, c);
state->pickcount++;
sbe = NULL;
be = state->shardd->backend[c].backend;
AN(be);
if (VRT_Healthy(state->ctx, be, &changed)) {
if (skip-- == 0) {
chosen = c;
sbe = &state->last;
} else {
sbe = &state->previous;
}
} else if (!healthy && skip-- == 0) {
chosen = c;
sbe = &state->last;
}
if (sbe == &state->last &&
state->last.hostid != -1)
memcpy(&state->previous, &state->last,
sizeof(state->previous));
if (sbe) {
sbe->hostid = c;
sbe->healthy = 1;
sbe->changed = changed;
}
if (chosen != -1)
break;
}
if (++(state->idx) == ringsz)
state->idx = 0;
}
return chosen;
}
vmod_healthy(VRT_CTX, VCL_BACKEND be)
{
CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
CHECK_OBJ_ORNULL(be, DIRECTOR_MAGIC);
return (VRT_Healthy(ctx, be));
}