Skip to content

Ports #7897 from core strategies to parent_select plugin. #8580

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
rob05c merged 1 commit into from
Jan 28, 2022
Merged

Ports #7897 from core strategies to parent_select plugin. #8580

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions include/ts/parentselectdefs.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,4 +57,5 @@ typedef struct {
bool responseIsRetryable;
bool goDirect;
bool parentIsProxy;
bool no_cache;
} TSResponseAction;
45 changes: 39 additions & 6 deletions plugins/experimental/parent_select/consistenthash.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,14 @@ PLNextHopConsistentHash::Init(const YAML::Node &n)
hash.clear();
rings.push_back(hash_ring);
}

if (ring_mode == PL_NH_PEERING_RING) {
if (groups != 2) {
PL_NH_Error("ring mode is '%s', requires two host groups (peering group and an upstream group).", peering_rings.data());
return false;
}
}

return true;
}

Expand Down Expand Up @@ -248,11 +256,13 @@ PLNextHopConsistentHash::getHashKey(uint64_t sm_id, TSMBuffer reqp, TSMLoc url,
}

static void
makeNextParentErr(const char **hostname, size_t *hostname_len, in_port_t *port)
makeNextParentErr(const char **hostname, size_t *hostname_len, in_port_t *port, bool *retry, bool *no_cache)
{
*hostname = nullptr;
*hostname_len = 0;
*port = 0;
*retry = false;
*no_cache = false;
Copy link
Copy Markdown
Contributor

@ywkaras ywkaras Jan 11, 2022

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is how people who didn't go to graduate school would do this: https://godbolt.org/z/M3z5fY46n

}

void *
Expand Down Expand Up @@ -280,7 +290,7 @@ PLNextHopConsistentHash::deleteTxn(void *txn)
void
PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exclude_hostname, size_t exclude_hostname_len,
in_port_t exclude_port, const char **out_hostname, size_t *out_hostname_len, in_port_t *out_port,
bool *out_retry, time_t now)
bool *out_retry, bool *out_no_cache, time_t now)
{
// TODO add logic in the strategy to track when someone is retrying, and not give it out to multiple threads at once, to prevent
// thundering retries See github issue #7485
Expand All @@ -296,15 +306,15 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
TSMLoc hdr;
ScopedFreeMLoc hdr_cleanup(&reqp, TS_NULL_MLOC, &hdr);
if (TSHttpTxnClientReqGet(txnp, &reqp, &hdr) == TS_ERROR) {
makeNextParentErr(out_hostname, out_hostname_len, out_port);
makeNextParentErr(out_hostname, out_hostname_len, out_port, out_retry, out_no_cache);
return;
}

TSMLoc parent_selection_url = TS_NULL_MLOC;
ScopedFreeMLoc parent_selection_url_cleanup(&reqp, TS_NULL_MLOC, &parent_selection_url);
if (TSUrlCreate(reqp, &parent_selection_url) != TS_SUCCESS) {
PL_NH_Error("nexthop failed to create url for parent_selection_url");
makeNextParentErr(out_hostname, out_hostname_len, out_port);
makeNextParentErr(out_hostname, out_hostname_len, out_port, out_retry, out_no_cache);
return;
}
if (TSHttpTxnParentSelectionUrlGet(txnp, reqp, parent_selection_url) != TS_SUCCESS) {
Expand All @@ -315,7 +325,7 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
ScopedFreeMLoc url_cleanup(&reqp, hdr, &url);
if (TSHttpHdrUrlGet(reqp, hdr, &url) != TS_SUCCESS) {
PL_NH_Error("failed to get header url, cannot find next hop");
makeNextParentErr(out_hostname, out_hostname_len, out_port);
makeNextParentErr(out_hostname, out_hostname_len, out_port, out_retry, out_no_cache);
return;
}

Expand All @@ -326,7 +336,7 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
if (TSHttpTxnConfigIntGet(txnp, TS_CONFIG_HTTP_PARENT_PROXY_RETRY_TIME, &retry_time) != TS_SUCCESS) {
// TODO get and cache on init, to prevent potential runtime failure?
PL_NH_Error("failed to get parent retry time, cannot find next hop");
makeNextParentErr(out_hostname, out_hostname_len, out_port);
makeNextParentErr(out_hostname, out_hostname_len, out_port, out_retry, out_no_cache);
return;
}

Expand Down Expand Up @@ -367,6 +377,12 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
cur_ring = state->last_group;
}
break;
case PL_NH_PEERING_RING:
ink_assert(groups == 2);
// look for the next parent on the
// upstream ring.
state->last_group = cur_ring = 1;
break;
case PL_NH_EXHAUST_RING:
default:
if (!wrapped) {
Expand Down Expand Up @@ -395,6 +411,13 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
const bool hostExists =
pRec ? (TSHostStatusGet(pRec->hostname.c_str(), pRec->hostname.size(), &hostStatus, nullptr) == TS_SUCCESS) : false;
state->first_choice_status = hostExists ? hostStatus : TSHostStatus::TS_HOST_STATUS_UP;
// if peering and the selected host is myself, change rings and search for an upstream
// parent.
if (ring_mode == PL_NH_PEERING_RING && TSHostnameIsSelf(pRec->hostname.c_str(), pRec->hostname.size()) == TS_SUCCESS) {
// switch to the upstream ring.
cur_ring = 1;
continue;
}
break;
}
} else {
Expand Down Expand Up @@ -531,6 +554,13 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
break;
}
state->retry = nextHopRetry;

// if using a peering ring mode and the parent selected came from the 'peering' group,
// cur_ring == 0, then if the config allows it, set the flag to not cache the result.
state->no_cache = ring_mode == PL_NH_PEERING_RING && !cache_peer_result && cur_ring == 0;
PL_NH_Debug(PL_NH_DEBUG_TAG, "[%" PRIu64 "] setting do not cache response from a peer per config: %s", sm_id,
state->no_cache ? "true" : "false");

ink_assert(state->hostname != nullptr);
ink_assert(state->port != 0);
PL_NH_Debug(PL_NH_DEBUG_TAG, "nextParent [%" PRIu64 "] state->result: %s Chosen parent: %.*s:%d", sm_id,
Expand All @@ -545,13 +575,16 @@ PLNextHopConsistentHash::next(TSHttpTxn txnp, void *strategyTxn, const char *exc
state->hostname_len = 0;
state->port = 0;
state->retry = false;
state->no_cache = false;
PL_NH_Debug(PL_NH_DEBUG_TAG, "nextParent [%" PRIu64 "] state->result: %s set hostname null port 0 retry false", sm_id,
PLNHParentResultStr[state->result]);
}

*out_hostname = state->hostname;
*out_hostname_len = state->hostname_len;
*out_port = state->port;
*out_retry = state->retry;
*out_no_cache = state->no_cache;
}

void
Expand Down
4 changes: 3 additions & 1 deletion plugins/experimental/parent_select/consistenthash.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,7 @@ struct PLNextHopConsistentHashTxn {
size_t hostname_len = 0;
in_port_t port = 0;
bool retry = false;
bool no_cache = false;
};

class PLNextHopConsistentHash : public PLNextHopSelectionStrategy
Expand All @@ -72,7 +73,8 @@ class PLNextHopConsistentHash : public PLNextHopSelectionStrategy
~PLNextHopConsistentHash();
bool Init(const YAML::Node &n);
void next(TSHttpTxn txnp, void *strategyTxn, const char *exclude_hostname, size_t exclude_hostname_len, in_port_t exclude_port,
const char **out_hostname, size_t *out_hostname_len, in_port_t *out_port, bool *out_retry, time_t now = 0) override;
const char **out_hostname, size_t *out_hostname_len, in_port_t *out_port, bool *out_retry, bool *out_no_cache,
time_t now = 0) override;
void mark(TSHttpTxn txnp, void *strategyTxn, const char *hostname, const size_t hostname_len, const in_port_t port,
const PLNHCmd status, const time_t now) override;
void *newTxn() override;
Expand Down
12 changes: 9 additions & 3 deletions plugins/experimental/parent_select/parent_select.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,7 @@ struct StrategyTxn {
size_t prev_host_len;
in_port_t prev_port;
bool prev_is_retry;
bool prev_no_cache;
};

int
Expand Down Expand Up @@ -81,9 +82,10 @@ handle_send_request(TSHttpTxn txnp, StrategyTxn *strategyTxn)
strategyTxn->prev_host_len = ra.hostname_len;
strategyTxn->prev_port = ra.port;
strategyTxn->prev_is_retry = ra.is_retry;
strategyTxn->prev_no_cache = ra.no_cache;

strategy->next(txnp, strategyTxn->txn, ra.hostname, ra.hostname_len, ra.port, &ra.hostname, &ra.hostname_len, &ra.port,
&ra.is_retry);
&ra.is_retry, &ra.no_cache);

ra.nextHopExists = strategy->nextHopExists(txnp);
ra.fail = !ra.nextHopExists; // failed is whether to fail and return to the client. failed=false means to retry the parent we set
Expand Down Expand Up @@ -121,6 +123,7 @@ mark_response(TSHttpTxn txnp, StrategyTxn *strategyTxn, TSHttpStatus status)
ra.hostname_len = strategyTxn->prev_host_len;
ra.port = strategyTxn->prev_port;
ra.is_retry = strategyTxn->prev_is_retry;
ra.no_cache = strategyTxn->prev_no_cache;
TSDebug(PLUGIN_NAME, "mark_response using prev %.*s:%d", int(ra.hostname_len), ra.hostname, ra.port);
} else {
TSHttpTxnResponseActionGet(txnp, &ra);
Expand Down Expand Up @@ -201,6 +204,7 @@ handle_read_response(TSHttpTxn txnp, StrategyTxn *strategyTxn)
strategyTxn->prev_host_len = 0;
strategyTxn->prev_port = 0;
strategyTxn->prev_is_retry = false;
strategyTxn->prev_no_cache = false;

TSHandleMLocRelease(resp, TS_NULL_MLOC, resp_hdr);
TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
Expand Down Expand Up @@ -235,6 +239,7 @@ handle_os_dns(TSHttpTxn txnp, StrategyTxn *strategyTxn)
strategyTxn->prev_host = nullptr;
strategyTxn->prev_port = 0;
strategyTxn->prev_is_retry = false;
strategyTxn->prev_no_cache = false;
TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
return TS_SUCCESS;
}
Expand All @@ -247,7 +252,7 @@ handle_os_dns(TSHttpTxn txnp, StrategyTxn *strategyTxn)
const size_t exclude_host_len = 0;
const in_port_t exclude_port = 0;
strategy->next(txnp, strategyTxn->txn, exclude_host, exclude_host_len, exclude_port, &ra.hostname, &ra.hostname_len, &ra.port,
&ra.is_retry);
&ra.is_retry, &ra.no_cache);

ra.fail = ra.hostname == nullptr; // failed is whether to immediately fail and return the client a 502. In this case: whether or
// not we found another parent.
Expand Down Expand Up @@ -419,6 +424,7 @@ TSRemapDoRemap(void *ih, TSHttpTxn txnp, TSRemapRequestInfo *rri)
strategyTxn->prev_host = nullptr;
strategyTxn->prev_port = 0;
strategyTxn->prev_is_retry = false;
strategyTxn->prev_no_cache = false;
TSContDataSet(cont, (void *)strategyTxn);

// TSHttpTxnHookAdd(txnp, TS_HTTP_READ_REQUEST_HDR_HOOK, cont);
Expand All @@ -434,7 +440,7 @@ TSRemapDoRemap(void *ih, TSHttpTxn txnp, TSRemapRequestInfo *rri)
constexpr const size_t exclude_host_len = 0;
constexpr const in_port_t exclude_port = 0;
strategy->next(txnp, strategyTxn->txn, exclude_host, exclude_host_len, exclude_port, &ra.hostname, &ra.hostname_len, &ra.port,
&ra.is_retry);
&ra.is_retry, &ra.no_cache);

if (ra.hostname == nullptr) {
// TODO make configurable
Expand Down
15 changes: 11 additions & 4 deletions plugins/experimental/parent_select/strategy.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -47,12 +47,13 @@
//

// ring mode strings
constexpr std::string_view alternate_rings = "alternate_ring";
constexpr std::string_view exhaust_rings = "exhaust_ring";
const std::string_view alternate_rings = "alternate_ring";
const std::string_view exhaust_rings = "exhaust_ring";
const std::string_view peering_rings = "peering_ring";

// health check strings
constexpr std::string_view active_health_check = "active";
constexpr std::string_view passive_health_check = "passive";
const std::string_view active_health_check = "active";
const std::string_view passive_health_check = "passive";

PLNextHopSelectionStrategy::PLNextHopSelectionStrategy(const std::string_view &name)
{
Expand Down Expand Up @@ -96,6 +97,10 @@ PLNextHopSelectionStrategy::Init(const YAML::Node &n)
ignore_self_detect = n["ignore_self_detect"].as<bool>();
}

if (n["cache_peer_result"]) {
cache_peer_result = n["cache_peer_result"].as<bool>();
}

// failover node.
YAML::Node failover_node;
if (n["failover"]) {
Expand All @@ -106,6 +111,8 @@ PLNextHopSelectionStrategy::Init(const YAML::Node &n)
ring_mode = PL_NH_ALTERNATE_RING;
} else if (ring_mode_val == exhaust_rings) {
ring_mode = PL_NH_EXHAUST_RING;
} else if (ring_mode_val == peering_rings) {
ring_mode = PL_NH_PEERING_RING;
} else {
ring_mode = PL_NH_ALTERNATE_RING;
PL_NH_Note("Invalid 'ring_mode' value, '%s', for the strategy named '%s', using default '%s'.", ring_mode_val.c_str(),
Expand Down
18 changes: 14 additions & 4 deletions plugins/experimental/parent_select/strategy.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,15 @@

constexpr const char *PL_NH_DEBUG_TAG = "plugin_nexthop";

// ring mode strings
extern const std::string_view alternate_rings;
extern const std::string_view exhaust_rings;
extern const std::string_view peering_rings;

// health check strings
extern const std::string_view active_health_check;
extern const std::string_view passive_health_check;

#define PL_NH_Debug(tag, fmt, ...) TSDebug(tag, "[%s:%d]: " fmt, __FILE__, __LINE__, ##__VA_ARGS__)
#define PL_NH_Error(fmt, ...) TSError("(%s) [%s:%d]: " fmt, PLUGIN_NAME, __FILE__, __LINE__, ##__VA_ARGS__)
#define PL_NH_Note(fmt, ...) TSDebug(PL_NH_DEBUG_TAG, "[%s:%d]: " fmt, __FILE__, __LINE__, ##__VA_ARGS__)
Expand All @@ -59,7 +68,7 @@ enum PLNHPolicyType {

enum PLNHSchemeType { PL_NH_SCHEME_NONE = 0, PL_NH_SCHEME_HTTP, PL_NH_SCHEME_HTTPS };

enum PLNHRingMode { PL_NH_ALTERNATE_RING = 0, PL_NH_EXHAUST_RING };
enum PLNHRingMode { PL_NH_ALTERNATE_RING = 0, PL_NH_EXHAUST_RING, PL_NH_PEERING_RING };

// response codes container
struct PLResponseCodes {
Expand Down Expand Up @@ -209,7 +218,7 @@ class TSNextHopSelectionStrategy
virtual const char *name() = 0;
virtual void next(TSHttpTxn txnp, void *strategyTxn, const char *exclude_hostname, size_t exclude_hostname_len,
in_port_t exclude_port, const char **out_hostname, size_t *out_hostname_len, in_port_t *out_port,
bool *out_retry, time_t now = 0) = 0;
bool *out_retry, bool *out_no_cache, time_t now = 0) = 0;
virtual void mark(TSHttpTxn txnp, void *strategyTxn, const char *hostname, const size_t hostname_len, const in_port_t port,
const PLNHCmd status, const time_t now = 0) = 0;
virtual bool nextHopExists(TSHttpTxn txnp) = 0;
Expand All @@ -234,9 +243,9 @@ class PLNextHopSelectionStrategy : public TSNextHopSelectionStrategy

virtual void next(TSHttpTxn txnp, void *strategyTxn, const char *exclude_hostname, size_t exclude_hostname_len,
in_port_t exclude_port, const char **out_hostname, size_t *out_hostname_len, in_port_t *out_port,
bool *out_retry, time_t now = 0) = 0;
bool *out_retry, bool *out_no_cache, time_t now = 0) = 0;
virtual void mark(TSHttpTxn txnp, void *strategyTxn, const char *hostname, const size_t hostname_len, const in_port_t port,
const PLNHCmd status, const time_t now = 0) = 0;
const PLNHCmd status, const time_t now = 0) = 0;
virtual bool nextHopExists(TSHttpTxn txnp);
virtual bool codeIsFailure(TSHttpStatus response_code);
virtual bool responseIsRetryable(unsigned int current_retry_attempts, TSHttpStatus response_code);
Expand All @@ -256,6 +265,7 @@ class PLNextHopSelectionStrategy : public TSNextHopSelectionStrategy
bool go_direct = true;
bool parent_is_proxy = true;
bool ignore_self_detect = false;
bool cache_peer_result = true;
PLNHSchemeType scheme = PL_NH_SCHEME_NONE;
PLNHRingMode ring_mode = PL_NH_ALTERNATE_RING;
PLResponseCodes resp_codes; // simple retry codes
Expand Down
13 changes: 10 additions & 3 deletions proxy/http/HttpTransact.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3642,9 +3642,16 @@ HttpTransact::handle_response_from_parent(State *s)
}
// the next hop strategy is configured not
// to cache a response from a next hop peer.
if (s->parent_result.do_not_cache_response) {
TxnDebug("http_trans", "response is from a next hop peer, do not cache.");
s->cache_info.action = CACHE_DO_NO_ACTION;
if (s->response_action.handled) {
if (s->response_action.action.no_cache) {
TxnDebug("http_trans", "plugin set response_action.no_cache, do not cache.");
s->cache_info.action = CACHE_DO_NO_ACTION;
}
} else {
if (s->parent_result.do_not_cache_response) {
TxnDebug("http_trans", "response is from a next hop peer, do not cache.");
s->cache_info.action = CACHE_DO_NO_ACTION;
}
}
handle_forward_server_connection_open(s);
break;
Expand Down