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zwoop pushed a commit to branch 9.0.x
in repository https://gitbox.apache.org/repos/asf/trafficserver.git
The following commit(s) were added to refs/heads/9.0.x by this push:
new 0050827 Add some stats collections to cache_promote.
0050827 is described below
commit 0050827a9c8f0f2a39f53986074f5afbc7b4a247
Author: John Rushford <[email protected]>
AuthorDate: Thu Dec 5 22:21:48 2019 +0000
Add some stats collections to cache_promote.
(cherry picked from commit 0da369c80e2a846e5e8fdbdc3b27c57f6af2e3dd)
---
doc/admin-guide/plugins/cache_promote.en.rst | 15 +++
plugins/cache_promote/cache_promote.cc | 148 ++++++++++++++++++++++++++-
2 files changed, 159 insertions(+), 4 deletions(-)
diff --git a/doc/admin-guide/plugins/cache_promote.en.rst
b/doc/admin-guide/plugins/cache_promote.en.rst
index aa831f1..7e3cbc4 100644
--- a/doc/admin-guide/plugins/cache_promote.en.rst
+++ b/doc/admin-guide/plugins/cache_promote.en.rst
@@ -49,6 +49,21 @@ If :option:`--policy` is set to ``lru`` the following
options are also available
The size (number of entries) of the LRU.
+.. option:: --stats-enable-with-id
+
+ Enables collecting statistics. The option requires an argument, the
+ remap-identifier. The remap-identifier is a string that is concatenated
+ to the stat name. The following stats are collected.
+
+* **plugin.cache_promote.${remap-identifier}.cache_hits** - Cache hit total,
available for all policies.
+* **plugin.cache_promote.${remap-identifier}.freelist_size** - Size of the
freelist when using the LRU policy.
+* **plugin.cache_promote.${remap-identifier}.lru_size** - Size of the LRU
when using the LRU policy.
+* **plugin.cache_promote.${remap-identifier}.lru_hit** - LRU hit count when
using the LRU policy.
+* **plugin.cache_promote.${remap-identifier}.lru_miss** - LRU miss count when
using the LRU policy.
+* **plugin.cache_promote.${remap-identifier}.lru_vacated** - count of LRU
entries removed to make room for a new request.
+* **plugin.cache_promote.${remap-identifier}.promoted** - count requests
promoted, available in all policies.
+* **plugin.cache_promote.${remap-identifier}.total_requests** - count of all
requests.
+
These two options combined with your usage patterns will control how likely a
URL is to become promoted to enter the cache.
diff --git a/plugins/cache_promote/cache_promote.cc
b/plugins/cache_promote/cache_promote.cc
index 2924b37..4a3aab5 100644
--- a/plugins/cache_promote/cache_promote.cc
+++ b/plugins/cache_promote/cache_promote.cc
@@ -28,11 +28,16 @@
#include <unordered_map>
#include <list>
+#include "tscore/ink_config.h"
+#include "tscore/ink_defs.h"
+#include "tscore/BufferWriter.h"
+
#include "ts/ts.h"
#include "ts/remap.h"
#include "tscore/ink_config.h"
#define MINIMUM_BUCKET_SIZE 10
+#define MAX_STAT_LENGTH (1 << 8)
static const char *PLUGIN_NAME = "cache_promote";
@@ -45,6 +50,7 @@ static const struct option longopt[] = {
{const_cast<char *>("sample"), required_argument, nullptr, 's'},
// For the LRU policy
{const_cast<char *>("buckets"), required_argument, nullptr, 'b'},
+ {const_cast<char *>("stats-enable-with-id"), required_argument, nullptr,
'e'},
{const_cast<char *>("hits"), required_argument, nullptr, 'h'},
// EOF
{nullptr, no_argument, nullptr, '\0'},
@@ -92,6 +98,42 @@ public:
return true;
}
+ int
+ create_stat(std::string_view name, std::string_view remap_identifier)
+ {
+ int stat_id = -1;
+ ts::LocalBufferWriter<MAX_STAT_LENGTH> stat_name;
+ stat_name.reset().clip(1);
+ stat_name.print("plugin.{}.{}.{}", PLUGIN_NAME, remap_identifier, name);
+ stat_name.extend(1).write('\0');
+
+ if (TS_ERROR == TSStatFindName(stat_name.data(), &stat_id)) {
+ stat_id = TSStatCreate(stat_name.data(), TS_RECORDDATATYPE_INT,
TS_STAT_NON_PERSISTENT, TS_STAT_SYNC_SUM);
+ if (TS_ERROR == stat_id) {
+ TSDebug(PLUGIN_NAME, "Error creating stat_name: %s", stat_name.data());
+ } else {
+ TSDebug(PLUGIN_NAME, "Created stat_name: %s, stat_id: %d",
stat_name.data(), stat_id);
+ }
+ }
+
+ return stat_id;
+ }
+ void
+ decrementStat(const int stat, const int amount)
+ {
+ if (stats_enabled) {
+ TSStatIntDecrement(stat, amount);
+ }
+ }
+
+ void
+ incrementStat(const int stat, const int amount)
+ {
+ if (stats_enabled) {
+ TSStatIntIncrement(stat, amount);
+ }
+ }
+
virtual ~PromotionPolicy() = default;
;
@@ -102,9 +144,16 @@ public:
}
// These are pure virtual
- virtual bool doPromote(TSHttpTxn txnp) = 0;
- virtual const char *policyName() const = 0;
- virtual void usage() const = 0;
+ virtual bool doPromote(TSHttpTxn txnp) = 0;
+ virtual const char *policyName() const = 0;
+ virtual void usage() const = 0;
+ virtual bool stats_add(const char *remap_id) = 0;
+
+ // when true stats are incremented.
+ bool stats_enabled = false;
+ int cache_hits_id = -1;
+ int promoted_id = -1;
+ int total_requests_id = -1;
private:
float _sample = 0.0;
@@ -120,6 +169,9 @@ public:
bool doPromote(TSHttpTxn /* txnp ATS_UNUSED */) override
{
TSDebug(PLUGIN_NAME, "ChancePolicy::doPromote(%f)", getSample());
+
+ incrementStat(promoted_id, 1);
+
return true;
}
@@ -134,6 +186,32 @@ public:
{
return "chance";
}
+
+ bool
+ stats_add(const char *remap_id) override
+ {
+ std::string_view remap_identifier = remap_id;
+ const std::tuple<std::string_view, int *> stats[] = {
+ {"cache_hits", &cache_hits_id},
+ {"promoted", &promoted_id},
+ {"total_requests", &total_requests_id},
+ };
+
+ if (nullptr == remap_id) {
+ TSError("[%s] no remap identifier specified for for stats, no stats will
be used", PLUGIN_NAME);
+ return false;
+ }
+
+ for (int ii = 0; ii < 3; ii++) {
+ std::string_view name = std::get<0>(stats[ii]);
+ int *id = std::get<1>(stats[ii]);
+ if ((*(id) = create_stat(name, remap_identifier)) == TS_ERROR) {
+ return false;
+ }
+ }
+
+ return true;
+ }
};
//////////////////////////////////////////////////////////////////////////////////////////////
@@ -280,6 +358,7 @@ public:
if (_map.end() != map_it) {
// We have an entry in the LRU
TSAssert(_list_size > 0); // mismatch in the LRUs hash and list,
shouldn't happen
+ incrementStat(lru_hit_id, 1);
if (++(map_it->second->second) >= _hits) {
// Promoted! Cleanup the LRU, and signal success. Save the promoted
entry on the freelist.
TSDebug(PLUGIN_NAME, "saving the LRUEntry to the freelist");
@@ -287,6 +366,9 @@ public:
++_freelist_size;
--_list_size;
_map.erase(map_it->first);
+ incrementStat(promoted_id, 1);
+ incrementStat(freelist_size_id, 1);
+ decrementStat(lru_size_id, 1);
ret = true;
} else {
// It's still not promoted, make sure it's moved to the front of the
list
@@ -295,19 +377,24 @@ public:
}
} else {
// New LRU entry for the URL, try to repurpose the list entry as much as
possible
+ incrementStat(lru_miss_id, 1);
if (_list_size >= _buckets) {
TSDebug(PLUGIN_NAME, "repurposing last LRUHash entry");
_list.splice(_list.begin(), _list, --_list.end());
_map.erase(&(_list.begin()->first));
+ incrementStat(lru_vacated_id, 1);
} else if (_freelist_size > 0) {
TSDebug(PLUGIN_NAME, "reusing LRUEntry from freelist");
_list.splice(_list.begin(), _freelist, _freelist.begin());
--_freelist_size;
++_list_size;
+ incrementStat(lru_size_id, 1);
+ decrementStat(freelist_size_id, 1);
} else {
TSDebug(PLUGIN_NAME, "creating new LRUEntry");
_list.push_front(NULL_LRU_ENTRY);
++_list_size;
+ incrementStat(lru_size_id, 1);
}
// Update the "new" LRUEntry and add it to the hash
_list.begin()->first = hash;
@@ -333,6 +420,33 @@ public:
return "LRU";
}
+ bool
+ stats_add(const char *remap_id) override
+ {
+ std::string_view remap_identifier = remap_id;
+ const std::tuple<std::string_view, int *> stats[] = {
+ {"cache_hits", &cache_hits_id}, {"freelist_size", &freelist_size_id},
+ {"lru_size", &lru_size_id}, {"lru_hit", &lru_hit_id},
+ {"lru_miss", &lru_miss_id}, {"lru_vacated", &lru_vacated_id},
+ {"promoted", &promoted_id}, {"total_requests", &total_requests_id},
+ };
+
+ if (nullptr == remap_id) {
+ TSError("[%s] no remap identifier specified for for stats, no stats will
be used", PLUGIN_NAME);
+ return false;
+ }
+
+ for (int ii = 0; ii < 8; ii++) {
+ std::string_view name = std::get<0>(stats[ii]);
+ int *id = std::get<1>(stats[ii]);
+ if ((*(id) = create_stat(name, remap_identifier)) == TS_ERROR) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
private:
unsigned _buckets = 1000;
unsigned _hits = 10;
@@ -342,6 +456,14 @@ private:
LRUMap _map;
LRUList _list, _freelist;
size_t _list_size = 0, _freelist_size = 0;
+
+ // internal stats ids
+ int freelist_size_id = -1;
+ int lru_size_id = -1;
+ int lru_hit_id = -1;
+ int lru_miss_id = -1;
+ int lru_vacated_id = -1;
+ int promoted_id = -1;
};
//////////////////////////////////////////////////////////////////////////////////////////////
@@ -363,7 +485,7 @@ public:
factory(int argc, char *argv[])
{
while (true) {
- int opt = getopt_long(argc, (char *const *)argv, "psbh", longopt,
nullptr);
+ int opt = getopt_long(argc, (char *const *)argv, "psbhe", longopt,
nullptr);
if (opt == -1) {
break;
@@ -379,6 +501,16 @@ public:
if (_policy) {
TSDebug(PLUGIN_NAME, "created remap with cache promotion policy =
%s", _policy->policyName());
}
+ } else if (opt == 'e') {
+ if (optarg == nullptr) {
+ TSError("[%s] the -%c option requires an argument, the remap
identifier.", PLUGIN_NAME, opt);
+ return false;
+ } else {
+ if (_policy && _policy->stats_add(optarg)) {
+ _policy->stats_enabled = true;
+ TSDebug(PLUGIN_NAME, "stats collection is enabled");
+ }
+ }
} else {
if (_policy) {
// The --sample (-s) option is allowed for all configs, but only
after --policy is specified.
@@ -440,9 +572,17 @@ cont_handle_policy(TSCont contp, TSEvent event, void
*edata)
default:
// Do nothing, just let it handle the lookup.
TSDebug(PLUGIN_NAME, "cache-status is %d (hit), nothing to do",
obj_status);
+
+ if (config->getPolicy()->stats_enabled) {
+ TSStatIntIncrement(config->getPolicy()->cache_hits_id, 1);
+ }
break;
}
}
+
+ if (config->getPolicy()->stats_enabled) {
+ TSStatIntIncrement(config->getPolicy()->total_requests_id, 1);
+ }
} else {
TSDebug(PLUGIN_NAME, "Request is an internal (plugin) request,
implicitly promoted");
}
