Answers.Body: <p>The fact that the error appears suddenly suggests that a <em>memcached</em> server was used by your system, but is not available anymore. The purpose of this server is to make the PHP execution faster (it stores values in memory that otherwise must be retrieved from the database).</p>
  
  <p>The cache is configured in the <em>civicrm.settings.php</em> file. Look for the variable <em>CIVICRM_DB_CACHE_CLASS</em>. The default value <em>"ArrayCache"</em> is useful for configurations that have no cache server running. The cache server connection details are found in the variables <em>CIVICRM_DB_CACHE_HOST</em> and  <em>CIVICRM_DB_CACHE_PORT</em>.</p>
  
  <p>More information about memcached can be found at <a href="http://memcached.org/" rel="nofollow noreferrer">http://memcached.org/</a>.</p>
  
  <p>Maybe the unix command</p>
  
  <pre><code>sudo systemctl start memcached 
  </code></pre>
  
  <p>is enough to get it running again.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-01-25T19:05:38.013Z
Answers.Text: Thank you. Running the command to restart memached seems to have done it!
Answers.UserDisplayName: Christia
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-01-24T17:54:57.033Z
Answers.LastActivityDate: 2017-01-24T17:54:57.033Z
Answers.UserDisplayName: Kainuk - CiviCooP
Body: <p>Suddenly my dev site is throwing a fatal error whenever I try to use a drush command, even including <code>drush version</code> or <code>drush cc all</code>. I'm on Drupal 7.50 and CiviCRM 4.7.15, Drush 7.0.0 and I am unaware of any differences between Dev and Production.</p>
  
  <p>What might be causing this? Here is the error message and backtrace:</p>
  
  <pre><code>root@web:/var/www/html/example/docroot# drush status
  Drush command terminated abnormally due to an unrecoverable error.                   [error]
  Sorry. A non-recoverable error has occurred.
  memcached set failed, wondering why?, _b7e34e2ca56a7e5553b56f61bcdd1b97civiroot 
  Array
  
  #0 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Utils/Cache/Memcached.php(121): CRM_Core_Error::fatal("memcached set failed, wondering why?, _b7e34e2ca56a7e5553b56f61bcdd1b97civiroot", (Array:0))
  #1 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Container/Basic.php(222): CRM_Utils_Cache_Memcached-&gt;set("civiroot", (Array:0))
  #2 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Container/Basic.php(132): CRM_Extension_Container_Basic-&gt;getRelPaths()
  #3 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Container/Collection.php(169): CRM_Extension_Container_Basic-&gt;getKeys()
  #4 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Container/Collection.php(145): CRM_Extension_Container_Collection-&gt;getKeysToContainer()
  #5 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Container/Collection.php(111): CRM_Extension_Container_Collection-&gt;getContainer("org.civicrm.module.cividiscount")
  #6 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Mapper.php(185): CRM_Extension_Container_Collection-&gt;getPath("org.civicrm.module.cividiscount")
  #7 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Mapper.php(224): CRM_Extension_Mapper-&gt;keyToInfo("org.civicrm.module.cividiscount")
  #8 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Mapper.php(302): CRM_Extension_Mapper-&gt;keyToPath("org.civicrm.module.cividiscount")
  #9 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/PseudoConstant.php(1788): CRM_Extension_Mapper-&gt;getActiveModuleFiles(FALSE)
  #10 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Utils/Hook.php(266): CRM_Core_PseudoConstant::getModuleExtensions()
  #11 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Utils/Hook/DrupalBase.php(102): CRM_Utils_Hook-&gt;requireCiviModules((Array:0))
  #12 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Utils/Hook/DrupalBase.php(81): CRM_Utils_Hook_DrupalBase-&gt;buildModuleList()
  #13 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Utils/Hook.php(1767): CRM_Utils_Hook_DrupalBase-&gt;invoke(1, (Array:152), NULL, NULL, NULL, NULL, NULL, "civicrm_entityTypes")
  #14 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/DAO/AllCoreTables.php(51): CRM_Utils_Hook::entityTypes((Array:152))
  #15 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/DAO/AllCoreTables.php(277): CRM_Core_DAO_AllCoreTables::init()
  #16 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/DAO/OptionGroup.php(179): CRM_Core_DAO_AllCoreTables::invoke("CRM_Core_DAO_OptionGroup", "fields_callback", (Array:8))
  #17 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/DAO.php(455): CRM_Core_DAO_OptionGroup::fields()
  #18 &lt;drupal_root&gt;/sites/all/modules/civicrm/packages/DB/DataObject.php(411): CRM_Core_DAO-&gt;table()
  #19 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/DAO.php(1082): DB_DataObject-&gt;find(TRUE)
  #20 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/Manager/Report.php(42): CRM_Core_DAO::getFieldValue("CRM_Core_DAO_OptionGroup", "report_template", "id", "name")
  #21 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/System.php(209): CRM_Extension_Manager_Report-&gt;__construct()
  #22 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Extension/System.php(195): CRM_Extension_System-&gt;getManager()
  #23 &lt;drupal_root&gt;/sites/all/modules/civicrm/Civi/Core/Container.php(365): CRM_Extension_System-&gt;getClassLoader()
  #24 &lt;drupal_root&gt;/sites/all/modules/civicrm/CRM/Core/Config.php(111): Civi\Core\Container::boot(TRUE)
  #25 &lt;drupal_root&gt;/sites/all/modules/civicrm/drupal/civicrm.module(218): CRM_Core_Config::singleton()
  #26 &lt;drupal_root&gt;/sites/all/modules/civicrm/drupal/modules/views/civicrm.views.inc(68): civicrm_initialize()
  #27 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/includes/cache.inc(93): civicrm_views_data_alter((Array:293))
  #28 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/includes/cache.inc(75): _views_fetch_data_build()
  #29 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/views.module(1293): _views_fetch_data(NULL, TRUE, FALSE)
  #30 &lt;drupal_root&gt;/profiles/commons/modules/contrib/entity/views/entity.views.inc(320): views_fetch_data()
  #31 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/includes/plugins.inc(414): entity_views_plugins()
  #32 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/includes/cache.inc(145): views_discover_plugins()
  #33 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/views.module(1304): _views_fetch_plugin_data(NULL, NULL, FALSE)
  #34 &lt;drupal_root&gt;/profiles/commons/modules/contrib/views/views.module(100): views_fetch_plugin_data()
  #35 &lt;drupal_root&gt;/includes/theme.inc(536): views_theme((Array:656), "module", "views", "profiles/commons/modules/contrib/views")
  #36 &lt;drupal_root&gt;/includes/theme.inc(689): _theme_process_registry((Array:656), "views", "module", "views", "profiles/commons/modules/contrib/views")
  #37 &lt;drupal_root&gt;/includes/theme.inc(325): _theme_build_registry(Object(stdClass), (Array:1), "phptemplate")
  #38 [internal function](): _theme_load_registry(Object(stdClass), (Array:1), "phptemplate")
  #39 &lt;drupal_root&gt;/includes/theme.inc(277): call_user_func_array("_theme_load_registry", (Array:3))
  #40 &lt;drupal_root&gt;/includes/theme.inc(411): theme_get_registry()
  #41 &lt;drupal_root&gt;/includes/theme.inc(395): ThemeRegistry-&gt;initializeRegistry()
  #42 &lt;drupal_root&gt;/includes/theme.inc(335): ThemeRegistry-&gt;__construct("theme_registry:runtime:example", "cache")
  #43 [internal function](): _theme_load_registry(Object(stdClass), (Array:1), "phptemplate", FALSE)
  #44 &lt;drupal_root&gt;/includes/theme.inc(277): call_user_func_array("_theme_load_registry", (Array:4))
  #45 &lt;drupal_root&gt;/includes/theme.inc(1020): theme_get_registry(FALSE)
  #46 &lt;drupal_root&gt;/sites/all/modules/contrib/seo_checklist/seo_checklist.module(54): theme("image", (Array:3))
  #47 [internal function](): seo_checklist_checklistapi_checklist_info()
  #48 &lt;drupal_root&gt;/includes/module.inc(957): call_user_func_array("seo_checklist_checklistapi_checklist_info", (Array:0))
  #49 &lt;drupal_root&gt;/sites/all/modules/contrib/checklistapi/checklistapi.module(66): module_invoke_all("checklistapi_checklist_info")
  #50 &lt;drupal_root&gt;/sites/all/modules/contrib/checklistapi/checklistapi.module(120): checklistapi_get_checklist_info()
  #51 &lt;drupal_root&gt;/sites/all/modules/contrib/checklistapi/checklistapi.module(98): checklistapi_menu()
  #52 [internal function](): checklistapi_init()
  #53 &lt;drupal_root&gt;/includes/module.inc(957): call_user_func_array("checklistapi_init", (Array:0))
  #54 &lt;drupal_root&gt;/includes/common.inc(5334): module_invoke_all("init")
  #55 &lt;drupal_root&gt;/includes/bootstrap.inc(2523): _drupal_bootstrap_full()
  #56 /usr/local/src/drush/lib/Drush/Boot/DrupalBoot7.php(70): drupal_bootstrap(7)
  #57 /usr/local/src/drush/includes/bootstrap.inc(308): Drush\Boot\DrupalBoot7-&gt;bootstrap_drupal_full()
  #58 /usr/local/src/drush/includes/bootstrap.inc(461): drush_bootstrap(5, 7)
  #59 /usr/local/src/drush/includes/bootstrap.inc(407): drush_bootstrap_max()
  #60 /usr/local/src/drush/lib/Drush/Boot/BaseBoot.php(54): drush_bootstrap_to_phase(-2)
  #61 /usr/local/src/drush/drush.php(70): Drush\Boot\BaseBoot-&gt;bootstrap_and_dispatch()
  #62 /usr/local/src/drush/drush.php(11): drush_main()
  #63 {main}
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-01-22T13:42:49.893Z
Comments.Text: Hi Christia, the error suggest you are using the PHP extension memcached. What is the value of CIVICRM_DB_CACHE_CLASS in your *civicrm.settings.php* file?
Comments.UserDisplayName: Kainuk - CiviCooP
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-01-23T17:26:50.057Z
Comments.Text: The default value is "ArrayCache". This is used when no external caching server is available.
Comments.UserDisplayName: Kainuk - CiviCooP
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-01-23T18:35:40.037Z
Comments.Text: You say the error manifested itself suddenly. That suggests a memcached server was running, but now it is not available anymore. Setting ArrayCache should get your CiviCRM running. After that, you can examine your _civicrm.settings.php_ file what the connection details of the server are (see CIVICRM_DB_CACHE_HOST and CIVICRM_DB_CACHE_PORT). The purpose of a cache is to make the PHP execution faster.
Comments.UserDisplayName: Kainuk - CiviCooP
Tags: <drupal><drush>
Title: Why do I get fatal error, memcached set failed?
ThreadText: # Why do I get fatal error, memcached set failed?
  
  (Asked by: username_0 on 2017-01-20)
  
  Suddenly my dev site is throwing a fatal error whenever I try to use a drush command, even including drush version or drush cc all. I'm on Drupal 7.50 and CiviCRM 4.7.15, Drush 7.0.0 and I am unaware of any differences between Dev and Production.
  What might be causing this? Here is the error message and backtrace:
  root@web:/var/www/html/example/docroot# drush status
  Drush command terminated abnormally due to an unrecoverable error.                   [error]
  Sorry. A non-recoverable error has occurred.
  memcached set failed, wondering why?, _b7e34e2ca56a7e5553b56f61bcdd1b97civiroot 
  Array
  
  #0 /sites/all/modules/civicrm/CRM/Utils/Cache/Memcached.php(121): CRM_Core_Error::fatal("memcached set failed, wondering why?, _b7e34e2ca56a7e5553b56f61bcdd1b97civiroot", (Array:0))
  #1 /sites/all/modules/civicrm/CRM/Extension/Container/Basic.php(222): CRM_Utils_Cache_Memcached->set("civiroot", (Array:0))
  #2 /sites/all/modules/civicrm/CRM/Extension/Container/Basic.php(132): CRM_Extension_Container_Basic->getRelPaths()
  #3 /sites/all/modules/civicrm/CRM/Extension/Container/Collection.php(169): CRM_Extension_Container_Basic->getKeys()
  #4 /sites/all/modules/civicrm/CRM/Extension/Container/Collection.php(145): CRM_Extension_Container_Collection->getKeysToContainer()
  #5 /sites/all/modules/civicrm/CRM/Extension/Container/Collection.php(111): CRM_Extension_Container_Collection->getContainer("org.civicrm.module.cividiscount")
  #6 /sites/all/modules/civicrm/CRM/Extension/Mapper.php(185): CRM_Extension_Container_Collection->getPath("org.civicrm.module.cividiscount")
  #7 /sites/all/modules/civicrm/CRM/Extension/Mapper.php(224): CRM_Extension_Mapper->keyToInfo("org.civicrm.module.cividiscount")
  #8 /sites/all/modules/civicrm/CRM/Extension/Mapper.php(302): CRM_Extension_Mapper->keyToPath("org.civicrm.module.cividiscount")
  #9 /sites/all/modules/civicrm/CRM/Core/PseudoConstant.php(1788): CRM_Extension_Mapper->getActiveModuleFiles(FALSE)
  #10 /sites/all/modules/civicrm/CRM/Utils/Hook.php(266): CRM_Core_PseudoConstant::getModuleExtensions()
  #11 /sites/all/modules/civicrm/CRM/Utils/Hook/DrupalBase.php(102): CRM_Utils_Hook->requireCiviModules((Array:0))
  #12 /sites/all/modules/civicrm/CRM/Utils/Hook/DrupalBase.php(81): CRM_Utils_Hook_DrupalBase->buildModuleList()
  #13 /sites/all/modules/civicrm/CRM/Utils/Hook.php(1767): CRM_Utils_Hook_DrupalBase->invoke(1, (Array:152), NULL, NULL, NULL, NULL, NULL, "civicrm_entityTypes")
  #14 /sites/all/modules/civicrm/CRM/Core/DAO/AllCoreTables.php(51): CRM_Utils_Hook::entityTypes((Array:152))
  #15 /sites/all/modules/civicrm/CRM/Core/DAO/AllCoreTables.php(277): CRM_Core_DAO_AllCoreTables::init()
  #16 /sites/all/modules/civicrm/CRM/Core/DAO/OptionGroup.php(179): CRM_Core_DAO_AllCoreTables::invoke("CRM_Core_DAO_OptionGroup", "fields_callback", (Array:8))
  #17 /sites/all/modules/civicrm/CRM/Core/DAO.php(455): CRM_Core_DAO_OptionGroup::fields()
  #18 /sites/all/modules/civicrm/packages/DB/DataObject.php(411): CRM_Core_DAO->table()
  #19 /sites/all/modules/civicrm/CRM/Core/DAO.php(1082): DB_DataObject->find(TRUE)
  #20 /sites/all/modules/civicrm/CRM/Extension/Manager/Report.php(42): CRM_Core_DAO::getFieldValue("CRM_Core_DAO_OptionGroup", "report_template", "id", "name")
  #21 /sites/all/modules/civicrm/CRM/Extension/System.php(209): CRM_Extension_Manager_Report->__construct()
  #22 /sites/all/modules/civicrm/CRM/Extension/System.php(195): CRM_Extension_System->getManager()
  #23 /sites/all/modules/civicrm/Civi/Core/Container.php(365): CRM_Extension_System->getClassLoader()
  #24 /sites/all/modules/civicrm/CRM/Core/Config.php(111): Civi\Core\Container::boot(TRUE)
  #25 /sites/all/modules/civicrm/drupal/civicrm.module(218): CRM_Core_Config::singleton()
  #26 /sites/all/modules/civicrm/drupal/modules/views/civicrm.views.inc(68): civicrm_initialize()
  #27 /profiles/commons/modules/contrib/views/includes/cache.inc(93): civicrm_views_data_alter((Array:293))
  #28 /profiles/commons/modules/contrib/views/includes/cache.inc(75): _views_fetch_data_build()
  #29 /profiles/commons/modules/contrib/views/views.module(1293): _views_fetch_data(NULL, TRUE, FALSE)
  #30 /profiles/commons/modules/contrib/entity/views/entity.views.inc(320): views_fetch_data()
  #31 /profiles/commons/modules/contrib/views/includes/plugins.inc(414): entity_views_plugins()
  #32 /profiles/commons/modules/contrib/views/includes/cache.inc(145): views_discover_plugins()
  #33 /profiles/commons/modules/contrib/views/views.module(1304): _views_fetch_plugin_data(NULL, NULL, FALSE)
  #34 /profiles/commons/modules/contrib/views/views.module(100): views_fetch_plugin_data()
  #35 /includes/theme.inc(536): views_theme((Array:656), "module", "views", "profiles/commons/modules/contrib/views")
  #36 /includes/theme.inc(689): _theme_process_registry((Array:656), "views", "module", "views", "profiles/commons/modules/contrib/views")
  #37 /includes/theme.inc(325): _theme_build_registry(Object(stdClass), (Array:1), "phptemplate")
  #38 [internal function](): _theme_load_registry(Object(stdClass), (Array:1), "phptemplate")
  #39 /includes/theme.inc(277): call_user_func_array("_theme_load_registry", (Array:3))
  #40 /includes/theme.inc(411): theme_get_registry()
  #41 /includes/theme.inc(395): ThemeRegistry->initializeRegistry()
  #42 /includes/theme.inc(335): ThemeRegistry->__construct("theme_registry:runtime:example", "cache")
  #43 [internal function](): _theme_load_registry(Object(stdClass), (Array:1), "phptemplate", FALSE)
  #44 /includes/theme.inc(277): call_user_func_array("_theme_load_registry", (Array:4))
  #45 /includes/theme.inc(1020): theme_get_registry(FALSE)
  #46 /sites/all/modules/contrib/seo_checklist/seo_checklist.module(54): theme("image", (Array:3))
  #47 [internal function](): seo_checklist_checklistapi_checklist_info()
  #48 /includes/module.inc(957): call_user_func_array("seo_checklist_checklistapi_checklist_info", (Array:0))
  #49 /sites/all/modules/contrib/checklistapi/checklistapi.module(66): module_invoke_all("checklistapi_checklist_info")
  #50 /sites/all/modules/contrib/checklistapi/checklistapi.module(120): checklistapi_get_checklist_info()
  #51 /sites/all/modules/contrib/checklistapi/checklistapi.module(98): checklistapi_menu()
  #52 [internal function](): checklistapi_init()
  #53 /includes/module.inc(957): call_user_func_array("checklistapi_init", (Array:0))
  #54 /includes/common.inc(5334): module_invoke_all("init")
  #55 /includes/bootstrap.inc(2523): _drupal_bootstrap_full()
  #56 /usr/local/src/drush/lib/Drush/Boot/DrupalBoot7.php(70): drupal_bootstrap(7)
  #57 /usr/local/src/drush/includes/bootstrap.inc(308): Drush\Boot\DrupalBoot7->bootstrap_drupal_full()
  #58 /usr/local/src/drush/includes/bootstrap.inc(461): drush_bootstrap(5, 7)
  #59 /usr/local/src/drush/includes/bootstrap.inc(407): drush_bootstrap_max()
  #60 /usr/local/src/drush/lib/Drush/Boot/BaseBoot.php(54): drush_bootstrap_to_phase(-2)
  #61 /usr/local/src/drush/drush.php(70): Drush\Boot\BaseBoot->bootstrap_and_dispatch()
  #62 /usr/local/src/drush/drush.php(11): drush_main()
  #63 {main}
  
  **Tags:** drupal, drush
  
  > **Comments:**
  > **username_1**: Hi username_0, the error suggest you are using the PHP extension memcached. What is the value of CIVICRM_DB_CACHE_CLASS in your *civicrm.settings.php* file?  
  > **username_1**: The default value is "ArrayCache". This is used when no external caching server is available.  
  > **username_1**: You say the error manifested itself suddenly. That suggests a memcached server was running, but now it is not available anymore. Setting ArrayCache should get your CiviCRM running. After that, you can examine your _civicrm.settings.php_ file what the connection details of the server are (see CIVICRM_DB_CACHE_HOST and CIVICRM_DB_CACHE_PORT). The purpose of a cache is to make the PHP execution faster.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2017-01-24. Score: 2 | Accepted answer
  
  The fact that the error appears suddenly suggests that a memcached server was used by your system, but is not available anymore. The purpose of this server is to make the PHP execution faster (it stores values in memory that otherwise must be retrieved from the database).
  The cache is configured in the civicrm.settings.php file. Look for the variable CIVICRM_DB_CACHE_CLASS. The default value "ArrayCache" is useful for configurations that have no cache server running. The cache server connection details are found in the variables CIVICRM_DB_CACHE_HOST and  CIVICRM_DB_CACHE_PORT.
  More information about memcached can be found at http://memcached.org/.
  Maybe the unix command
  sudo systemctl start memcached 
  
  is enough to get it running again.
  
  > **Comments:**
  > **username_0**: Thank you. Running the command to restart memached seems to have done it!  
  
  ---
  
  