What does ttl stand for? Is it Time To Live? -----Original Message----- From: Bjoern Petri [mailto:bjoern.pe...@sundevil.de] Sent: Tuesday, October 07, 2014 1:05 PM To: dev@celix.apache.org Subject: Re: svn commit: r1627454 - in /celix/trunk/remote_services/discovery_etcd/private: include/etcd.h src/etcd.c src/etcd_watcher.c
Hi Alexander, the ttl specifies the specified time to live for the key in seconds. The discovery_etcd announces itself with a ttl of 30 seconds. If the etcd-watch of the amdatu discovery etcd-implementation (not the endpoint_discovery_poller) takes more time than this, the described behavior occurs. Because the etcd-watch is nothing else than a long poll, the timeout values has to be set accordingly. The celix discovery-etcd implementation currently uses 10 seconds for that. Regards, Bjoern On 2014-10-07 18:26, Alexander Broekhuis wrote: > Hi Bjoern, > > I've updated to trunk, and now when I try to run a Celix -> Amdatu > example using Etcd, it doesn't work as expected. > I haven't investigated this deeply, but when I disable the TTL code > (revert the changes from this (and the fix) commit, it works again. So > somewhere in this part something is going on. > > What happens is that the service is picked up by Amdatu, is added, but > after some time is removed again. How is the TTL supposed to work? Is > this a consequence of the Amdatu poller not polling quick enough wrt > TTL set in Celix? > > Thanks, > > 2014-09-25 6:56 GMT+02:00 <bpe...@apache.org>: > >> Author: bpetri >> Date: Thu Sep 25 04:56:28 2014 >> New Revision: 1627454 >> >> URL: http://svn.apache.org/r1627454 >> Log: >> >> CELIX-152: add ttl support for etcd >> >> >> Modified: >> celix/trunk/remote_services/discovery_etcd/private/include/etcd.h >> celix/trunk/remote_services/discovery_etcd/private/src/etcd.c >> >> celix/trunk/remote_services/discovery_etcd/private/src/etcd_watcher.c >> >> Modified: >> celix/trunk/remote_services/discovery_etcd/private/include/etcd.h >> URL: >> http://svn.apache.org/viewvc/celix/trunk/remote_services/discovery_et >> cd/private/include/etcd.h?rev=1627454&r1=1627453&r2=1627454&view=diff >> >> ===================================================================== >> ========= >> --- celix/trunk/remote_services/discovery_etcd/private/include/etcd.h >> (original) >> +++ celix/trunk/remote_services/discovery_etcd/private/include/etcd.h >> Thu >> Sep 25 04:56:28 2014 >> @@ -21,7 +21,7 @@ >> bool etcd_init(char* server, int port); bool etcd_get(char* key, >> char* value, char*action, int* modifiedIndex); bool >> etcd_getNodes(char* directory, char** nodeNames, int* size); -bool >> etcd_set(char* key, char* value); >> +bool etcd_set(char* key, char* value, int ttl); >> bool etcd_del(char* key); >> bool etcd_watch(char* key, int index, char* action, char* prevValue, >> char* value); >> >> >> Modified: >> celix/trunk/remote_services/discovery_etcd/private/src/etcd.c >> URL: >> http://svn.apache.org/viewvc/celix/trunk/remote_services/discovery_et >> cd/private/src/etcd.c?rev=1627454&r1=1627453&r2=1627454&view=diff >> >> ===================================================================== >> ========= >> --- celix/trunk/remote_services/discovery_etcd/private/src/etcd.c >> (original) >> +++ celix/trunk/remote_services/discovery_etcd/private/src/etcd.c Thu >> Sep >> 25 04:56:28 2014 >> @@ -5,16 +5,17 @@ >> #include <curl/curl.h> >> #include <jansson.h> >> >> - >> - >> #include "etcd.h" >> >> +#define DEFAULT_CURL_TIMEOUT 10 >> +#define DEFAULT_CURL_CONECTTIMEOUT 10 >> + >> typedef enum { >> GET, PUT, DELETE >> } request_t; >> >> static char* etcd_server = NULL; >> -static int etcd_port = NULL; >> +static int etcd_port = 0; >> >> struct MemoryStruct { >> char *memory; >> @@ -44,8 +45,8 @@ static int performRequest(char* url, req >> CURLcode res = 0; >> >> curl = curl_easy_init(); >> - curl_easy_setopt(curl, CURLOPT_TIMEOUT, 10); >> - curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 10); >> + curl_easy_setopt(curl, CURLOPT_TIMEOUT, DEFAULT_CURL_TIMEOUT); >> + curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, >> DEFAULT_CURL_CONECTTIMEOUT); >> curl_easy_setopt(curl, CURLOPT_URL, url); >> curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); >> curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, callback); @@ >> -175,7 +176,7 @@ bool etcd_getNodes(char* directory, char } >> >> //set >> -bool etcd_set(char* key, char* value) { >> +bool etcd_set(char* key, char* value, int ttl) { >> json_error_t error; >> json_t* js_root; >> json_t* js_node; >> @@ -190,7 +191,11 @@ bool etcd_set(char* key, char* value) { >> reply.size = 0; /* no data at this point */ >> >> snprintf(url, MAX_URL_LENGTH, "http://%s:%d/v2/keys/%s";, >> etcd_server, etcd_port, key); >> - snprintf(request, MAX_CONTENT_LENGTH, "value=%s", value); >> + >> + if (ttl > 0) >> + snprintf(request, MAX_CONTENT_LENGTH, "value=%s", value); >> + else >> + snprintf(request, MAX_CONTENT_LENGTH, "value=%s;ttl=%d", >> value, ttl); >> >> res = performRequest(url, PUT, WriteMemoryCallback, request, >> (void*) &reply); >> if (res == CURLE_OPERATION_TIMEDOUT) { >> >> Modified: >> celix/trunk/remote_services/discovery_etcd/private/src/etcd_watcher.c >> URL: >> http://svn.apache.org/viewvc/celix/trunk/remote_services/discovery_et >> cd/private/src/etcd_watcher.c?rev=1627454&r1=1627453&r2=1627454&view= >> diff >> >> ===================================================================== >> ========= >> --- >> celix/trunk/remote_services/discovery_etcd/private/src/etcd_watcher.c >> (original) >> +++ >> celix/trunk/remote_services/discovery_etcd/private/src/etcd_watcher.c >> Thu Sep 25 04:56:28 2014 >> @@ -53,6 +53,10 @@ struct etcd_watcher { >> #define CFG_ETCD_SERVER_PORT "DISCOVERY_ETCD_SERVER_PORT" >> #define DEFAULT_ETCD_SERVER_PORT 4001 >> >> +// be careful - this should be higher than the curl timeout >> +#define CFG_ETCD_TTL "DISCOVERY_ETCD_TTL" >> +#define DEFAULT_ETCD_TTL 30 >> + >> >> // note that the rootNode shouldn't have a leading slash static >> celix_status_t etcdWatcher_getRootPath(char* rootNode) { @@ -132,6 >> +136,49 @@ static celix_status_t etcdWatcher_addAlr >> return status; >> } >> >> + >> +static celix_status_t etcdWatcher_addOwnFramework(bundle_context_pt >> context) >> +{ >> + celix_status_t status = CELIX_BUNDLE_EXCEPTION; >> + char localNodePath[MAX_LOCALNODE_LENGTH]; >> + char* endpoints = NULL; >> + char* ttlStr = NULL; >> + int ttl; >> + >> + // register own framework >> + if ((status = etcdWatcher_getLocalNodePath(context, >> &localNodePath[0])) != CELIX_SUCCESS) { >> + return status; >> + } >> + >> + if ((bundleContext_getProperty(context, >> + DISCOVERY_POLL_ENDPOINTS, >> &endpoints) != CELIX_SUCCESS) || !endpoints) { >> + endpoints = DEFAULT_POLL_ENDPOINTS; >> + } >> + >> + if ((bundleContext_getProperty(context, CFG_ETCD_TTL, &ttlStr) >> + != >> CELIX_SUCCESS) || !ttlStr) { >> + ttl = DEFAULT_ETCD_TTL; >> + } >> + else >> + { >> + char* endptr = ttlStr; >> + errno = 0; >> + ttl = strtol(ttlStr, &endptr, 10); >> + if (*endptr || errno != 0) { >> + ttl = DEFAULT_ETCD_TTL; >> + } >> + } >> + >> + if (etcd_set(localNodePath, endpoints, ttl) == false) >> + { >> + fw_log(logger, OSGI_FRAMEWORK_LOG_WARNING, "Cannot register >> local >> discovery"); >> + } >> + else >> + { >> + status = CELIX_SUCCESS; >> + } >> + >> + return status; >> +} >> + >> /* >> * performs (blocking) etcd_watch calls to check for >> * changing discovery endpoint information within etcd. >> @@ -161,6 +208,8 @@ static void* etcdWatcher_run(void* data) >> fw_log(logger, >> OSGI_FRAMEWORK_LOG_INFO, "Unexpected action: %s", action); >> } >> } >> + // update own framework uuid in any case; >> + etcdWatcher_addOwnFramework(watcher->context); >> } >> >> return NULL; >> @@ -174,11 +223,10 @@ celix_status_t etcdWatcher_create(endpoi >> etcd_watcher_pt *watcher) { >> celix_status_t status = CELIX_SUCCESS; >> - char localNodePath[MAX_LOCALNODE_LENGTH]; >> + >> char* etcd_server = NULL; >> char* etcd_port_string = NULL; >> - int etcd_port = NULL; >> - char* endpoints = NULL; >> + int etcd_port = 0; >> >> if (poller == NULL) { >> return CELIX_BUNDLE_EXCEPTION; @@ -211,9 +259,6 @@ >> celix_status_t etcdWatcher_create(endpoi >> } >> } >> >> - if ((bundleContext_getProperty(context, >> DISCOVERY_POLL_ENDPOINTS, >> &endpoints) != CELIX_SUCCESS) || !endpoints) { >> - endpoints = DEFAULT_POLL_ENDPOINTS; >> - } >> >> >> if (etcd_init(etcd_server, etcd_port) == false) @@ -221,17 >> +266,7 @@ celix_status_t etcdWatcher_create(endpoi >> return CELIX_BUNDLE_EXCEPTION; >> } >> >> - // register own framework >> - if ((status = etcdWatcher_getLocalNodePath(context, >> &localNodePath[0])) != CELIX_SUCCESS) { >> - return status; >> - } >> - >> - if (etcd_set(localNodePath, endpoints) == false) >> - { >> - fw_log(logger, OSGI_FRAMEWORK_LOG_WARNING, "Cannot >> register local discovery"); >> - } >> - >> - >> + etcdWatcher_addOwnFramework(context); >> >> if ((status = >> celixThreadMutex_create(&(*watcher)->watcherLock, >> NULL)) != CELIX_SUCCESS) { >> return status; >> >> >>
