Re: waiting for client write

[Pavan Pusuluri <pavan.pusuluri@xxxxxxxxx>]

Hi Ayub

So, i understand the client are blocked waiting on a write to the database!

What does the blocked thread signature say?

Are you pre-creating any partitions?

Are you experiencing Timed outs??

What is the driver you are using now? If you are using Jdbc, can you update your driver to the latest version?

Regards

Pavan

On Fri, Jun 11, 2021, 11:28 AM Ayub Khan <ayub.hp@xxxxxxxxx> wrote:

Vijay, 

Both tomcat and postgresql are on the same region as that of the database server. It is an RDS so I do not have shell access to it.

Jeff,

The tomcat profile is suggesting that it's waiting for a response from the database server. 

Tomcat and RDS are in the same availability region as  eu-central-1a

On Wed, Jun 9, 2021 at 5:47 PM Ayub Khan <ayub.hp@xxxxxxxxx> wrote:

attached is the screenshot of RDS performance insights for AWS and it shows high waiting client writes. The api performance is slow. I read that this might be due to IOPS on RDS. However we have 80k IOPS on this test RDS. 

Below is the query which is being load tested

SELECT

                       a.menu_item_id,
                       a.menu_item_name,
                       a.menu_item_category_id,
                       b.menu_item_category_desc,
                       c.menu_item_variant_id,
                       c.menu_item_variant_type_id,
                       c.price,
                       c.size_id,
                       c.parent_menu_item_variant_id,
                       d.menu_item_variant_type_desc,
                       e.size_desc,
                       f.currency_code,
                       a.image,
                       a.mark_id,
                       m.mark_name

                     FROM .menu_item_category AS b, .menu_item_variant AS c,
                       .menu_item_variant_type AS d, .item_size AS e, .restaurant AS f,
                       .menu_item AS a

                       LEFT OUTER JOIN .mark AS m
                         ON (a.mark_id = m.mark_id)

                     WHERE a.menu_item_category_id = b.menu_item_category_id AND a.menu_item_id = c.menu_item_id AND
                           c.menu_item_variant_type_id = d.menu_item_variant_type_id AND d.is_hidden = 'false' AND
                           c.size_id = e.size_id AND a.restaurant_id = f.restaurant_id AND f.restaurant_id = 1528 AND
                           (a.menu_item_category_id = NULL OR NULL IS NULL)

                           AND c.menu_item_variant_id = (SELECT min(menu_item_variant_id)
                                                         FROM .menu_item_variant
                                                         WHERE menu_item_id = a.menu_item_id AND deleted = 'N'
                                                         LIMIT 1) AND a.active = 'Y'
                           AND (CONCAT_WS('', ',', a.hidden_branch_ids, ',') NOT LIKE CONCAT_WS('', '%,4191,%') OR
                                NULL IS NULL)
   AND .is_menu_item_available(a.menu_item_id, 'Y') = 'Y'

   ORDER BY a.row_order, menu_item_id;

--Ayub

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