| <?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE html |
| PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
| <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> |
| <head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> |
| |
| <meta name="copyright" content="(C) Copyright 2025" /> |
| <meta name="DC.rights.owner" content="(C) Copyright 2025" /> |
| <meta name="DC.Type" content="concept" /> |
| <meta name="DC.Title" content="Impala Client Access" /> |
| <meta name="DC.Relation" scheme="URI" content="../topics/impala_impala_shell.html" /> |
| <meta name="DC.Relation" scheme="URI" content="../topics/impala_odbc.html" /> |
| <meta name="DC.Relation" scheme="URI" content="../topics/impala_jdbc.html" /> |
| <meta name="DC.Relation" scheme="URI" content="../topics/impala_query_results_spooling.html" /> |
| <meta name="prodname" content="Impala" /> |
| <meta name="version" content="Impala 3.4.x" /> |
| <meta name="DC.Format" content="XHTML" /> |
| <meta name="DC.Identifier" content="intro_client" /> |
| <link rel="stylesheet" type="text/css" href="../commonltr.css" /> |
| <title>Impala Client Access</title> |
| </head> |
| <body id="intro_client"> |
| |
| |
| <h1 class="title topictitle1" id="ariaid-title1">Impala Client Access</h1> |
| |
| |
| |
| |
| <div class="body conbody"> |
| |
| <p class="p"> |
| Application developers have a number of options to interface with Impala. The core |
| development language with Impala is SQL. You can also use Java or other languages to |
| interact with Impala through the standard JDBC and ODBC interfaces used by many business |
| intelligence tools. For specialized kinds of analysis, you can supplement the Impala |
| built-in functions by writing user-defined functions in C++ or Java. |
| </p> |
| |
| |
| <p class="p"> |
| You can connect and submit requests to the Impala through: |
| </p> |
| |
| |
| <ul class="ul"> |
| <li class="li"> |
| The impala-shell interactive command interpreter |
| </li> |
| |
| |
| <li class="li"> |
| The Hue web-based user interface |
| </li> |
| |
| |
| <li class="li"> |
| JDBC |
| </li> |
| |
| |
| <li class="li"> |
| ODBC |
| </li> |
| |
| </ul> |
| |
| |
| <p class="p"> |
| Impala clients can connect to the Coordinator Impala Daemon (<code class="ph codeph">impalad</code>) via |
| HiveServer2 over HTTP or over the TCP binary. Both HTTP and binary support the Kerberos |
| SPNEGO and LDAP for authentication to Impala. See below for the default ports and the |
| Impala flags to change the ports. |
| </p> |
| |
| |
| <div class="p"> |
| <table cellpadding="4" cellspacing="0" summary="" id="intro_client__simpletable_tr2_gnt_43b" border="1" class="simpletable"><col style="width:22.675736961451246%" /><col style="width:23.356009070294785%" /><col style="width:53.96825396825397%" /><thead></thead><tbody><tr class="strow"> |
| |
| <td style="vertical-align:top;" class="stentry"><strong class="ph b">Protocol</strong> |
| |
| </td> |
| |
| |
| <td style="vertical-align:top;" class="stentry"><strong class="ph b">Default Port</strong> |
| |
| </td> |
| |
| |
| <td style="vertical-align:top;" class="stentry"><strong class="ph b">Flag to Specify an Alternate Port</strong> |
| |
| </td> |
| |
| |
| </tr> |
| <tr class="strow"> |
| |
| <td style="vertical-align:top;" class="stentry">HTTP</td> |
| |
| |
| <td style="vertical-align:top;" class="stentry">28000</td> |
| |
| |
| <td style="vertical-align:top;" class="stentry"><code class="ph codeph">‑‑hs2_http_port</code> |
| |
| </td> |
| |
| |
| </tr> |
| <tr class="strow"> |
| |
| <td style="vertical-align:top;" class="stentry">Binary TCP</td> |
| |
| |
| <td style="vertical-align:top;" class="stentry">21050</td> |
| |
| |
| <td style="vertical-align:top;" class="stentry"><code class="ph codeph">‑‑hs2_port</code> |
| |
| </td> |
| |
| |
| </tr> |
| </tbody></table> |
| |
| </div> |
| |
| |
| <p class="p"> |
| Each <code class="ph codeph">impalad</code> daemon process, running on separate nodes in a cluster, |
| listens to <a class="xref" href="impala_ports.html#ports">several ports</a> for incoming requests: |
| </p> |
| |
| |
| <ul class="ul"> |
| <li class="li"> |
| Requests from <code class="ph codeph">impala-shell</code> and Hue are routed to the |
| <code class="ph codeph">impalad</code> daemons through the same port. |
| </li> |
| |
| |
| <li class="li"> |
| The <code class="ph codeph">impalad</code> daemons listen on separate ports for JDBC and ODBC |
| requests. |
| </li> |
| |
| </ul> |
| |
| |
| <div class="section" id="intro_client__section_egg_wjt_f3b"><h2 class="title sectiontitle">Impala Startup Options for Client Connections</h2> |
| |
| |
| |
| <p class="p"> |
| Use the following flags when starting Impala Daemon coordinator to control client |
| connections to Impala. |
| </p> |
| |
| |
| <dl class="dl"> |
| |
| |
| <dt class="dt dlterm"> |
| --accepted_client_cnxn_timeout |
| </dt> |
| |
| |
| <dd class="dd"> |
| Controls how Impala treats new connection requests if it has run out of the number |
| of threads configured by <code class="ph codeph">--fe_service_threads</code>. |
| <p class="p"> |
| If <code class="ph codeph">--accepted_client_cnxn_timeout > 0</code>, new connection requests |
| are rejected if Impala can't get a server thread within the specified (in seconds) |
| timeout. |
| </p> |
| |
| |
| <p class="p"> |
| If <code class="ph codeph">--accepted_client_cnxn_timeout=0</code>, i.e. no timeout, clients |
| wait indefinitely to open the new session until more threads are available. |
| </p> |
| |
| |
| <p class="p"> |
| The default timeout is 5 minutes. |
| </p> |
| |
| |
| <p class="p"> |
| The timeout applies only to client facing thrift servers, i.e., HS2 and Beeswax |
| servers. |
| </p> |
| |
| </dd> |
| |
| |
| |
| |
| |
| |
| <dt class="dt dlterm"> |
| --disconnected_session_timeout |
| </dt> |
| |
| |
| <dd class="dd"> |
| When a HiveServer2 session has had no open connections for longer than this value, |
| the session will be closed, and any associated queries will be unregistered. |
| <p class="p"> |
| Specify the value in hours. |
| </p> |
| |
| |
| <p class="p"> |
| The default value is 1 hour. |
| </p> |
| |
| |
| <p class="p"> |
| This flag does not apply to Beeswax clients. When a Beeswax client connection is |
| closed, Impala closes the session associated with that connection. |
| </p> |
| |
| </dd> |
| |
| |
| |
| |
| |
| |
| <dt class="dt dlterm"> |
| --fe_service_threads |
| </dt> |
| |
| |
| <dd class="dd"> |
| Specifies the maximum number of concurrent client connections allowed. The default |
| value is 64 with which 64 queries can run simultaneously. |
| <p class="p"> |
| If you have more clients trying to connect to Impala than the value of this |
| setting, the later arriving clients have to wait for the duration specified by |
| <code class="ph codeph">--accepted_client_cnxn_timeout</code>. You can increase this value to |
| allow more client connections. However, a large value means more threads to be |
| maintained even if most of the connections are idle, and it could negatively |
| impact query latency. Client applications should use the connection pool to avoid |
| need for large number of sessions. |
| </p> |
| |
| </dd> |
| |
| |
| |
| |
| |
| |
| <dt class="dt dlterm"> |
| --hs2_http_port |
| </dt> |
| |
| |
| <dd class="dd"> |
| Specifies the port for clients to connect to Impala server over HTTP. |
| <p class="p"> |
| The default port is 28000. |
| </p> |
| |
| |
| <p class="p"> |
| You can disable the HTTP end point for clients by setting the flag to |
| <code class="ph codeph">0</code>. |
| </p> |
| |
| |
| <p class="p"> |
| To enable TLS/SSL for HiveServer2 HTTP endpoint use |
| <code class="ph codeph">--ssl_server_certificate</code> and <code class="ph codeph">--ssl_private_key</code>. |
| See <a class="xref" href="impala_ssl.html#ssl">Configuring TLS/SSL for Impala</a> for detail. |
| </p> |
| |
| </dd> |
| |
| |
| |
| |
| |
| |
| <dt class="dt dlterm"> |
| --idle_client_poll_period_s |
| </dt> |
| |
| |
| <dd class="dd"> |
| The value of this setting specifies how frequently Impala polls to check if a client |
| connection is idle and closes it if the connection is idle. A client connection is |
| idle if all sessions associated with the client connection are idle. |
| <p class="p"> |
| By default, <code class="ph codeph">--idle_client_poll_period_s</code> is set to 30 seconds. |
| </p> |
| |
| |
| <p class="p"> |
| If <code class="ph codeph">--idle_client_poll_period_s</code> is set to 0, idle client connections |
| stay open until explicitly closed by the clients. |
| </p> |
| |
| |
| <p class="p"> |
| The connection will only be closed if all the associated sessions are idle or |
| closed. Sessions cannot be idle unless either the flag |
| <code class="ph codeph">--idle_session_timeout</code> or the |
| <code class="ph codeph">IDLE_SESSION_TIMEOUT</code> query option is set to greater than 0. If |
| idle session timeout is not configured, a session cannot become idle by |
| definition, and therefore its connection stays open until the client explicitly |
| closes it. |
| </p> |
| |
| </dd> |
| |
| |
| |
| |
| |
| |
| <dt class="dt dlterm"> |
| --max_cookie_lifetime_s |
| </dt> |
| |
| |
| <dd class="dd"> |
| Starting in Impala 3.4.0, Impala uses cookies for authentication when clients |
| connect via HiveServer2 over HTTP. Use the <code class="ph codeph">--max_cookie_lifetime_s</code> |
| startup flag to control how long generated cookies are valid for. |
| <p class="p"> |
| Specify the value in seconds. |
| </p> |
| |
| <p class="p"> |
| The default value is 1 day. |
| </p> |
| |
| |
| <p class="p"> |
| Setting the flag to <code class="ph codeph">0</code> disables cookie support. |
| </p> |
| |
| |
| <p class="p"> |
| When an unexpired cookie is successfully verified, the user name contained in the |
| cookie is set on the connection. |
| </p> |
| |
| |
| <p class="p"> |
| Each <code class="ph codeph">impalad</code> uses its own key to generate the signature, so |
| clients that reconnect to a different <code class="ph codeph">impalad</code> have to |
| re-authenticate. |
| </p> |
| |
| |
| <p class="p"> |
| On a single <code class="ph codeph">impalad</code>, cookies are valid across sessions and |
| connections. |
| </p> |
| |
| </dd> |
| |
| |
| |
| |
| |
| |
| <dt class="dt dlterm"> |
| --max_hs2_sessions_per_user |
| </dt> |
| |
| |
| <dd class="dd"> |
| Specifies the maximum allowed number of HiveServer2 sessions that can be |
| opened by any single connected user on a coordinator. |
| <p class="p"> |
| The default is -1. Setting to -1 or 0 disables this feature. |
| </p> |
| |
| </dd> |
| |
| |
| |
| </dl> |
| |
| |
| </div> |
| |
| |
| </div> |
| |
| |
| <div class="related-links"> |
| <ul class="ullinks"> |
| <li class="link ulchildlink"><strong><a href="../topics/impala_impala_shell.html">Using the Impala Shell (impala-shell Command)</a></strong><br /> |
| </li> |
| <li class="link ulchildlink"><strong><a href="../topics/impala_odbc.html">Configuring Impala to Work with ODBC</a></strong><br /> |
| </li> |
| <li class="link ulchildlink"><strong><a href="../topics/impala_jdbc.html">Configuring Impala to Work with JDBC</a></strong><br /> |
| </li> |
| <li class="link ulchildlink"><strong><a href="../topics/impala_query_results_spooling.html">Spooling Impala Query Results</a></strong><br /> |
| </li> |
| </ul> |
| </div></body> |
| </html> |
