<div dir="ltr">Hello Daren,<br><br>Thank you for your comments. <br><br>We use MariaDB v11.4.3 which seems to be fully compatible with KEA.<br><br>In MariaDB logs, we only see such entries :<br>> 2025-01-09 9:06:50 8232949 [Warning] Aborted connection 8232949 to db: 'kea' user: 'kea_user' host: '1.2.3.4' real ip: '5.6.7.8' (Got an error reading communication packets)<br><br>As we don't see such errors by connecting directly a KEA node to a MariaDB node, it seems that the issue only occurs when using HAPROXY in front of the GALERA Cluster. <br><br>Also, according the following link, it seems that we should have to configure 4 KEA instances (as we use 4 MariaDB instances which each KEA instance being connected to one MariaDB node) ???<a href="https://gitlab.isc.org/isc-projects/kea/-/issues/1746">https://gitlab.isc.org/isc-projects/kea/-/issues/1746</a> <br><br>For troubleshooting this issue, we currently configured HAPROXY with only 1 MariaDB node and source IP stickiness, the aims being :<br>* to persist the KEA database connection with the same MariaDB node <br>* to be able to connect KEA to another MariaDB node if the current node fails<br><br>We can confirm that the error occurs in such a simple situation (with only one database node) and we don't understand why KEA generates DATABASE_MYSQL_FATAL_ERROR messages.<br><br>Could you confirm if we can use HAPROXY in such a manner ?<br>Are there specific settings to activate in KEA and/or HAPROXY ? <br>Or finaly, is it better not to use HAPROXY in such a scenario ?<br><br>Any advice for configuring this kind of KEA cluster will be appreciated.<br>Kind regards.</div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">Le mer. 8 janv. 2025 à 22:59, Darren Ankney <<a href="mailto:darren.ankney@gmail.com">darren.ankney@gmail.com</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hi Sébastien,<br></div><div><br></div><div>The frequent disconnections could be anything. Is there anything in the MySQL logs? Also, is this MySQL or MariaDB? MySQL 8 has some performance issues that affect Kea pretty badly (See here: <a href="https://kea.readthedocs.io/en/kea-2.6.1/arm/admin.html#mysql-5-7-vs-mysql-8-vs-mariadb-10-and-11" target="_blank">https://kea.readthedocs.io/en/kea-2.6.1/arm/admin.html#mysql-5-7-vs-mysql-8-vs-mariadb-10-and-11</a>)</div><div><br></div><div>If you haven't already found them, there are a couple of articles about MySQL clusters and Kea:</div><div><a href="https://kb.isc.org/docs/getting-started-with-galera-or-percona-for-kea" target="_blank">https://kb.isc.org/docs/getting-started-with-galera-or-percona-for-kea</a></div><div><a href="https://kb.isc.org/docs/experimental-mysql-clusters-for-kea" target="_blank">https://kb.isc.org/docs/experimental-mysql-clusters-for-kea</a> (this one might not be relevant)<br></div><div><br></div><div>Thank you,</div><div>Darren Ankney<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Jan 8, 2025 at 4:51 AM Sébastien Nauer via Kea-users <<a href="mailto:kea-users@lists.isc.org" target="_blank">kea-users@lists.isc.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hello,<br><br>We are experiencing issues with configuring a KEA cluster in high-availability mode with a GALERA Cluster database backend.<br><br>As we'd like to use the database cluster for managing leases synchronization :<br><ul><li>we configured KEA High Availability mode like this for disabling lease sync & update :</li></ul><font face="monospace" size="1">"high-availability": [<br> {<br> "this-server-name": "kea01",<br> "mode": "load-balancing",<br> "heartbeat-delay": 10000,<br> "max-response-delay": 10000,<br> "max-ack-delay": 5000,<br> "max-unacked-clients": 5,<br> "send-lease-updates": false,<br> "sync-leases": false,<br> "sync-page-limit": 10000,<br> "sync-timeout": 30000,<br> "multi-threading": {<br> "enable-multi-threading": true,<br> "http-dedicated-listener": true,<br> "http-listener-threads": 0,<br> "http-client-threads": 0<br> },<br> "peers": [<br> {<br> "name": "kea0&",<br> "url": "<a href="http://1.2.3.4:8080/" target="_blank">http://1.2.3.4:8080/</a>",<br> "role": "primary",<br> "auto-failover": true<br> },<br> {<br> "name": "kea04",<br> "url": "<a href="http://5.6.7.8:8080/" target="_blank">http://5.6.7.8:8080/</a>",<br> "role": "secondary",<br> "auto-failover": true<br> }<br> ]<br> }<br>]</font><br><ul><li>we configured the lease database like this for connecting to the database cluster :</li></ul></div><font face="monospace" size="1">"lease-database": {<br> "type": "mysql",<br> "name": "kea",<br> "user": "KEA_USER",<br> "password": "KEA_PASSWORD",<br> "host": "1.1.1.1",<br> "max-reconnect-tries" : 10,<br> "reconnect-wait-time" : 30000<br>},</font><div><ul><li>we tried to connect to the database backend :</li><ul><li>through a VIP with load balancing</li><li>through HAPROXY with / without load balancing</li><li><br></li></ul></ul>When we start KEA service and the servers start, KEA logs show a lot of DATABASE_MYSQL_FATAL_ERROR messages like this : <br><br><font face="monospace" size="1">2025-01-07 16:18:42.483 ERROR [kea-dhcp4.database/4349.0x34cf8b308500] DATABASE_MYSQL_FATAL_ERROR Unrecoverable MySQL error occurred: unable to execute for <SELECT h.host_id, h.dhcp_identifier, h.dhcp_identifier_type, h.dhcp4_subnet_id, h.dhcp6_subnet_id, h.ipv4_address, h.hostname, h.dhcp4_client_classes, h.dhcp6_client_classes, h.user_context, h.dhcp4_next_server, h.dhcp4_server_hostname, h.dhcp4_boot_file_name, h.auth_key, o.option_id, o.code, o.value, o.formatted_value, <a href="http://o.space" target="_blank">o.space</a>, o.persistent, o.cancelled, o.user_context FROM hosts AS h LEFT JOIN dhcp4_options AS o ON h.host_id = o.host_id WHERE h.dhcp4_subnet_id = ? AND h.dhcp_identifier_type = ? AND h.dhcp_identifier = ? ORDER BY h.host_id, o.option_id>, reason: Server has gone away (error code: 2006).<br>2025-01-07 16:18:43.533 INFO [kea-dhcp4.dhcp4/4349.0x34cf8aa12000] DHCP4_DB_RECONNECT_LOST_CONNECTION database connection lost.<br>2025-01-07 16:18:43.533 INFO [kea-dhcp4.hosts/4349.0x34cf8aa12000] DHCPSRV_MYSQL_HOST_DB opening MySQL hosts database: host=10.194.50.12 max-reconnect-tries=10 name=prod_kea password=***** reconnect-wait-time=30000 type=mysql universe=4 user=keaCluster<br>2025-01-07 16:18:43.586 INFO [kea-dhcp4.dhcp4/4349.0x34cf8aa12000] DHCP4_DB_RECONNECT_SUCCEEDED database connection recovered.</font><br><br>As we noticed that the database connection is frequently lost for no apparent reason we suspect that there is an issue with using persistent database connections through a VIP with load balancing (maybe related to multithreading also)</div><div><br>Has anyone successfully configured such a setup ? How ?<br>What do you suggest for avoiding this error message and configuring a high availability DHCP cluster with a high availability database cluster ? <br><br>Any feedback from the community will be appreciated !<br>Kind regards<br><br><br></div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><br><table width="320" cellspacing="0" cellpadding="0" style="font-size:12.8px;font-family:Times;margin:0px;padding:0px"><tbody><tr><td width="100" style="width:100px;padding:0px"><img src="cid:ii_15f531873412908f" alt="Inline-Bild 1" width="100" height="100"><br></td><td width="10" style="width:10px"> </td><td valign="top" style="padding:0px"><br><table cellspacing="0" cellpadding="0" style="padding:0px;margin:0px;font-family:"Lucida Grande",sans-serif;font-size:12px;color:rgb(176,176,176);border-collapse:collapse"><tbody><tr style="margin:0px;padding:0px"><td style="padding:0px;white-space:nowrap"><strong><a href="mailto:snauer@hotcity.lu" style="color:rgb(17,85,204);border:medium" target="_blank"><span style="color:rgb(3,54,108)">Sébastien NAUER</span></a></strong><span style="color:rgb(224,224,224)">|</span> <span style="color:rgb(85,85,85)">Technical Manager</span></td></tr><tr style="margin:0px;padding:0px;color:rgb(176,164,155)"><td style="padding:0px;white-space:nowrap"><a href="http://goo.gl/maps/GqQcf" style="color:rgb(176,176,176);border:medium" target="_blank">11, Avenue Guillaume <span style="color:rgb(224,224,224)">|</span> L-1651 Luxembourg</a></td></tr><tr style="margin:0px;padding:0px;color:rgb(176,164,155)"><td style="font-family:"Lucida Grande",sans-serif;padding:0px;white-space:nowrap"><a style="color:rgb(176,176,176)">Phone: <span style="color:rgb(192,192,192)">(+352)</span> 2663 2660 </a><span style="color:rgb(224,224,224)">|</span> <a style="color:rgb(176,176,176)">Fax: <span style="color:rgb(192,192,192)">(+352)</span> 2663 2665</a></td></tr><tr style="margin:0px;padding:0px;color:rgb(176,164,155)"><td style="font-family:"Lucida Grande",sans-serif;padding:0px;white-space:nowrap"><a href="https://www.facebook.com/hotcity.lu" style="color:rgb(192,192,192);border:medium" target="_blank">Facebook</a> <span style="color:rgb(224,224,224)">|</span> <a href="https://twitter.com/hotcity_wifi" style="color:rgb(192,192,192);border:medium" target="_blank">Twitter</a></td></tr></tbody></table></td></tr></tbody></table></div></div></div></div></div></div>
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</blockquote></div><div><br clear="all"></div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><br><table width="320" cellspacing="0" cellpadding="0" style="font-size:12.8px;font-family:Times;margin:0px;padding:0px"><tbody><tr><td width="100" style="width:100px;padding:0px"><img src="cid:ii_15f531873412908f" alt="Inline-Bild 1" width="100" height="100"><br></td><td width="10" style="width:10px"> </td><td valign="top" style="padding:0px"><br><table cellspacing="0" cellpadding="0" style="padding:0px;margin:0px;font-family:"Lucida Grande",sans-serif;font-size:12px;color:rgb(176,176,176);border-collapse:collapse"><tbody><tr style="margin:0px;padding:0px"><td style="padding:0px;white-space:nowrap"><strong><a href="mailto:snauer@hotcity.lu" style="color:rgb(17,85,204);border:none" target="_blank"><span style="color:rgb(3,54,108)">Sébastien NAUER</span></a></strong><span style="color:rgb(224,224,224)">|</span> <span style="color:rgb(85,85,85)">Technical Manager</span></td></tr><tr style="margin:0px;padding:0px;color:rgb(176,164,155)"><td style="padding:0px;white-space:nowrap"><a href="http://goo.gl/maps/GqQcf" style="color:rgb(176,176,176);border:none" target="_blank">11, Avenue Guillaume <span style="color:rgb(224,224,224)">|</span> L-1651 Luxembourg</a></td></tr><tr style="margin:0px;padding:0px;color:rgb(176,164,155)"><td style="font-family:"Lucida Grande",sans-serif;padding:0px;white-space:nowrap"><a style="color:rgb(176,176,176)">Phone: <span style="color:rgb(192,192,192)">(+352)</span> 2663 2660 </a><span style="color:rgb(224,224,224)">|</span> <a style="color:rgb(176,176,176)">Fax: <span style="color:rgb(192,192,192)">(+352)</span> 2663 2665</a></td></tr><tr style="margin:0px;padding:0px;color:rgb(176,164,155)"><td style="font-family:"Lucida Grande",sans-serif;padding:0px;white-space:nowrap"><a href="https://www.facebook.com/hotcity.lu" style="color:rgb(192,192,192);border:none" target="_blank">Facebook</a> <span style="color:rgb(224,224,224)">|</span> <a href="https://twitter.com/hotcity_wifi" style="color:rgb(192,192,192);border:none" target="_blank">Twitter</a></td></tr></tbody></table></td></tr></tbody></table></div></div></div></div></div>