<div dir="ltr">Thank you for the clarifications.<div><br><div>So my understanding currently is : </div><div>-----------</div><div>1. database '<b>primary</b>' node failure is the event controlling the failover process. (executing failover.sh)</div><div>2. Watchdog `<b>MASTER</b>` failure only causes the VIP to move to another node. That is unless of course watchdog master is also the </div><div>current pgpool primary node, in which case a failover will be triggered.</div><div>3. <b>esc.sh</b> and <b>desc.sh </b>only concerns the watchdog MASTER/STANDBY</div><div><br></div><div>Am I correct?</div><div><div><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><b>Thanks</b><br></div><i>Gopi</i><br></div></div></div><br></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, May 29, 2023 at 2:10 PM Tatsuo Ishii <<a href="mailto:ishii@sraoss.co.jp">ishii@sraoss.co.jp</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">>> Hi pgpool experts,<br>
>> <br>
>> Can you please clarify the below?<br>
>> *During failover, Is the '*primary*' or '*MASTER*' or ' *load_balance_node*<br>
>> failure taken into account?*<br>
> <br>
> It's hard to answer your question as the question is too vague. Anyway I try it...<br>
> <br>
> - primary failure is taken into account because it triggers failover.<br>
> See <a href="https://www.pgpool.net/docs/44/en/html/runtime-config-failover.html" rel="noreferrer" target="_blank">https://www.pgpool.net/docs/44/en/html/runtime-config-failover.html</a> for more details.<br>
> <br>
> - MASTER and other watchdog nodes are taken into account in failover.<br>
> See<br>
> <a href="https://www.pgpool.net/docs/44/en/html/runtime-watchdog-config.html#CONFIG-WATCHDOG-FAILOVER-BEHAVIOR" rel="noreferrer" target="_blank">https://www.pgpool.net/docs/44/en/html/runtime-watchdog-config.html#CONFIG-WATCHDOG-FAILOVER-BEHAVIOR</a><br>
> for more details.<br>
> <br>
> - Load balance node is not taken into account in streaming replication mode.<br>
> See note #2 in <a href="https://www.pgpool.net/docs/44/en/html/runtime-config-failover.html" rel="noreferrer" target="_blank">https://www.pgpool.net/docs/44/en/html/runtime-config-failover.html</a> for more details.<br>
<br>
Sorry, I meant "Load balance node is taken into account".<br>
<br>
>> <br>
>> *Thanks*<br>
>> *Gopi*<br>
>> <br>
>> <br>
>> On Tue, May 16, 2023 at 10:56 AM Gopikrishnan <<a href="mailto:nksgopikrishnan@gmail.com" target="_blank">nksgopikrishnan@gmail.com</a>><br>
>> wrote:<br>
>> <br>
>>> Thank you for your response!<br>
>>><br>
>>> Can you also kindly clarify this:<br>
>>> During failover, Is the '*primary*' or '*MASTER*' or '<br>
>>> *load_balance_node* failure taken into account?<br>
>>><br>
>>> *Thanks*<br>
>>> *Gopi*<br>
>>><br>
>>><br>
>>> On Tue, May 16, 2023 at 10:26 AM Bo Peng <<a href="mailto:pengbo@sraoss.co.jp" target="_blank">pengbo@sraoss.co.jp</a>> wrote:<br>
>>><br>
>>>> Hi,<br>
>>>><br>
>>>> > Regd. which I couldn't gather much from the docs at:<br>
>>>> > <a href="https://www.pgpool.net/docs/pgpool-II-4.0.4/" rel="noreferrer" target="_blank">https://www.pgpool.net/docs/pgpool-II-4.0.4/</a><br>
>>>> ><br>
>>>> ><br>
>>>> > 1. primary<br>
>>>> > 2. MASTER<br>
>>>> > 3. load_balance_node<br>
>>>><br>
>>>> 1. primary:<br>
>>>> It is the role of *PostgreSQL* nodes.<br>
>>>> The role of PostgreSQL nodes can be primary or standby<br>
>>>> in streaming replication mode.<br>
>>>><br>
>>>> 2. MASTER:<br>
>>>> I think you are asking the status name shown<br>
>>>> in the result of pcp_watchdog_info command.<br>
>>>> The status name MASTER/STANDBY is the role of *Pgpool-II* node.<br>
>>>> If you have multiple Pgpool-II nodes using watchdog feature,<br>
>>>> one of them will be elected as MASTER and others will be STANDBY.<br>
>>>><br>
>>>> 3. load_balance_node<br>
>>>> Pgpool-II supports for load balancing of SELECT queries.<br>
>>>> When a session starts, pgpool will randomly elect one PostgreSQL node<br>
>>>> as the load balance node (load_balance_node) and routes SELECTs to<br>
>>>> the load_balance_node.<br>
>>>><br>
>>>> On Mon, 15 May 2023 15:54:53 +0530<br>
>>>> Gopikrishnan <<a href="mailto:nksgopikrishnan@gmail.com" target="_blank">nksgopikrishnan@gmail.com</a>> wrote:<br>
>>>><br>
>>>> > Hi folks,<br>
>>>> ><br>
>>>> > Need your help in clearing a confusion regd. basic terminologies:<br>
>>>> ><br>
>>>> > Regd. which I couldn't gather much from the docs at:<br>
>>>> > <a href="https://www.pgpool.net/docs/pgpool-II-4.0.4/" rel="noreferrer" target="_blank">https://www.pgpool.net/docs/pgpool-II-4.0.4/</a><br>
>>>> ><br>
>>>> ><br>
>>>> > 1. primary<br>
>>>> > 2. MASTER<br>
>>>> > 3. load_balance_node<br>
>>>> ><br>
>>>> > I have a pgpool with 3 nodes. I have a confusion between the pgpool<br>
>>>> primary and<br>
>>>> > the watchdog *MASTER* and the `*load_balance_node*`<br>
>>>> ><br>
>>>> > In my setup, the pgpool primary node (according to show pool_nodes<br>
>>>> output)<br>
>>>> > is : *10.108.104.31, *and also the node designated *load_balance_node*.<br>
>>>> ><br>
>>>> > While the MASTER node, according to pgpool watchdog, is:<br>
>>>> *10.108.104.32* And<br>
>>>> > the *cluster virtual IP* is attached to this node.<br>
>>>> ><br>
>>>> > I have the following questions in mind:<br>
>>>> ><br>
>>>> ><br>
>>>> > 1. What do the terms '*primary*' and '*MASTER*' and<br>
>>>> *load_balance_node*<br>
>>>> > mean?<br>
>>>> > 2. During failover, Is the '*primary*' or '*MASTER*' or '<br>
>>>> > *load_balance_node* failure taken into account?<br>
>>>> > 3. What is the difference (or any relation) between the '*primary*'<br>
>>>> and '<br>
>>>> > *MASTER*' and *load_balance_node* nodes?<br>
>>>> > 4. If the cluster virtual IP is on the non '*primary*' node,<br>
>>>> wouldn't it<br>
>>>> > affect the performance of the HA setup?<br>
>>>> ><br>
>>>> > Below are the outputs for *show pool_nodes *and* watchdog *info:<br>
>>>> ><br>
>>>> > psql -h delegateIP -p 9999 -U pgpool postgres -c "show pool_nodes"<br>
>>>> > Password for user pgpool:<br>
>>>> > node_id | hostname | port | status | lb_weight | role |<br>
>>>> > select_cnt | load_balance_node | replication_delay |<br>
>>>> ><br>
>>>> last_status_change---------+---------------+------+--------+-----------+---------+------------+-------------------+-------------------+---------------------<br>
>>>> > 0 | 10.108.104.31 | 5432 | up | 0.333333 | primary | 0<br>
>>>> > | true | 0 | 2023-05-12 12:07:13<br>
>>>> > 1 | 10.108.104.32 | 5432 | up | 0.333333 | standby | 0<br>
>>>> > | false | 0 | 2023-05-12 12:07:13<br>
>>>> > 2 | 10.108.104.33 | 5432 | down | 0.333333 | standby | 0<br>
>>>> > | false | 0 | 2023-05-12 12:07:13<br>
>>>> > (3 rows)<br>
>>>> ><br>
>>>> > And the Watchdog info:<br>
>>>> ><br>
>>>> > pcp_watchdog_info -h localhost -vw -U pgpool<br>
>>>> > Watchdog Cluster Information<br>
>>>> > Total Nodes : 3<br>
>>>> > Remote Nodes : 2<br>
>>>> > Quorum state : QUORUM EXIST<br>
>>>> > Alive Remote Nodes : 2<br>
>>>> > VIP up on local node : NO<br>
>>>> > Master Node Name : <a href="http://vm-104-32.eng.dev.com:9999" rel="noreferrer" target="_blank">vm-104-32.eng.dev.com:9999</a> Linux<br>
>>>> <a href="http://vm-104-32.eng.dev.com" rel="noreferrer" target="_blank">vm-104-32.eng.dev.com</a><br>
>>>> > Master Host Name : 10.108.104.32<br>
>>>> ><br>
>>>> > Watchdog Node Information<br>
>>>> > Node Name : <a href="http://vm-104-31.eng.dev.com:9999" rel="noreferrer" target="_blank">vm-104-31.eng.dev.com:9999</a> Linux <a href="http://vm-104-31.eng.dev.com" rel="noreferrer" target="_blank">vm-104-31.eng.dev.com</a><br>
>>>> > Host Name : <a href="http://vm-104-31.eng.dev.com" rel="noreferrer" target="_blank">vm-104-31.eng.dev.com</a><br>
>>>> > Delegate IP : 10.108.104.34<br>
>>>> > Pgpool port : 9999<br>
>>>> > Watchdog port : 9000<br>
>>>> > Node priority : 1<br>
>>>> > Status : 7<br>
>>>> > Status Name : STANDBY<br>
>>>> ><br>
>>>> > Node Name : <a href="http://vm-104-32.eng.dev.com:9999" rel="noreferrer" target="_blank">vm-104-32.eng.dev.com:9999</a> Linux <a href="http://vm-104-32.eng.dev.com" rel="noreferrer" target="_blank">vm-104-32.eng.dev.com</a><br>
>>>> > Host Name : 10.108.104.32<br>
>>>> > Delegate IP : 10.108.104.34<br>
>>>> > Pgpool port : 9999<br>
>>>> > Watchdog port : 9000<br>
>>>> > Node priority : 1<br>
>>>> > Status : 4<br>
>>>> > Status Name : MASTER<br>
>>>> ><br>
>>>> > Node Name : <a href="http://vm-104-33.eng.dev.com:9999" rel="noreferrer" target="_blank">vm-104-33.eng.dev.com:9999</a> Linux <a href="http://vm-104-33.eng.dev.com" rel="noreferrer" target="_blank">vm-104-33.eng.dev.com</a><br>
>>>> > Host Name : 10.108.104.33<br>
>>>> > Delegate IP : 10.108.104.34<br>
>>>> > Pgpool port : 9999<br>
>>>> > Watchdog port : 9000<br>
>>>> > Node priority : 1<br>
>>>> > Status : 7<br>
>>>> > Status Name : STANDBY<br>
>>>> ><br>
>>>> ><br>
>>>> ><br>
>>>> > *Thanks & Regards*<br>
>>>> > *Gopi*<br>
>>>><br>
>>>><br>
>>>> --<br>
>>>> Bo Peng <<a href="mailto:pengbo@sraoss.co.jp" target="_blank">pengbo@sraoss.co.jp</a>><br>
>>>> SRA OSS LLC<br>
>>>> <a href="https://www.sraoss.co.jp/" rel="noreferrer" target="_blank">https://www.sraoss.co.jp/</a><br>
>>>><br>
>>><br>
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</blockquote></div>