+++ This bug was initially created as a clone of Bug #1729811 +++

Description of problem:

If a VM has several users logged in, the engine cannot update the vm_dynamic table via the UpdateVmDynamic procedure, leaving everything out of sync, which can be dangerous.

The problem is guest_cur_user_name is limited to 255 chars. If there are enough users logged in to exceed this, the SQL procedure fails.

CREATE OR REPLACE FUNCTION UpdateVmDynamic (
    v_app_list TEXT,
    v_guest_cur_user_name VARCHAR(255),
    ...

2019-07-15 11:14:18,926+10 ERROR [org.ovirt.engine.core.dal.dbbroker.BatchProcedureExecutionConnectionCallback] (EE-ManagedThreadFactory-engineScheduled-Thread-33) [] Can't execute batch: Batch entry 0 select * from public.updatevmdynamic(CAST ('kernel-3.10.0-957.12.2.el7,cloud-init-18.2-1.el7.centos.2,ovirt-guest-agent-common-1.0.16-1.el7,qemu-guest-agent-2.12.0' AS text),CAST ('' AS varchar),CAST (NULL AS varchar),CAST (NULL AS varchar),CAST (NULL AS uuid),CAST ('3.10.0-957.12.2.el7.x86_64' AS varchar),CAST (NULL AS uuid),CAST ('b89ccd0c-7e74-415f-a7c4-f8f3abced3fb'::uuid AS uuid),CAST (1 AS int4),CAST ('f3e6d39a-a404-4a1e-8729-9d37563f8205'::uuid AS uuid),CAST ('engine.kvm' AS varchar),CAST ('192.168.150.253 fe80::5054:ff:fe19:c1ff' AS varchar),CAST ('engine.kvm' AS varchar),CAST (NULL AS timestamptz),CAST (NULL AS timestamptz),CAST (0 AS int8),CAST ('2019-07-05 13:24:42.316+10' AS timestamptz),CAST ('TRUE' AS bool),CAST (0 AS int4),CAST (0 AS int4),CAST (0 AS int4),CAST ('' AS varchar),CAST (NULL AS int4),CAST (0 AS int4),CAST (5 AS int4),CAST (NULL AS varchar),CAST (-1848952666 AS int4),CAST (NULL AS numeric),CAST (NULL AS varchar),CAST ('FALSE' AS bool),CAST ('FALSE' AS bool),CAST (NULL AS varchar),CAST (NULL AS varchar),CAST (NULL AS varchar),CAST (NULL AS varchar),CAST (-1 AS int4),CAST (2 AS int4),CAST (5901 AS int4),CAST (5902 AS int4),CAST ('192.168.150.1' AS varchar),CAST (5900 AS int4),CAST ('192.168.150.1' AS varchar),CAST (0 AS int4),CAST (0 AS int4),CAST (600 AS int4),CAST ('AEST' AS varchar),CAST (1 AS int4),CAST ('' AS varchar),CAST ('CentOS Linux' AS varchar),CAST ('3.10.0-957.12.2.el7.x86_64' AS varchar),CAST ('Linux' AS varchar),CAST ('7' AS varchar),CAST ('[]' AS text)) as result was aborted: ERROR: value too long for type character varying(255)
  Where: SQL statement "UPDATE vm_dynamic
    SET app_list = v_app_list,
        guest_cur_user_name = v_guest_cur_user_name,
        console_cur_user_name = v_console_cur_user_name,
        runtime_name = v_runtime_name,
        console_user_id = v_console_user_id,
        guest_os = v_guest_os,
        migrating_to_vds = v_migrating_to_vds,
        run_on_vds = v_run_on_vds,
        status = v_status,
        vm_host = v_vm_host,
        vm_ip = v_vm_ip,
        vm_fqdn = v_vm_fqdn,
        last_start_time = v_last_start_time,
        boot_time = v_boot_time,
        downtime = v_downtime,
        last_stop_time = v_last_stop_time,
        acpi_enable = v_acpi_enable,
        session = v_session,
        boot_sequence = v_boot_sequence,
        utc_diff = v_utc_diff,
        client_ip = v_client_ip,
        guest_requested_memory = v_guest_requested_memory,
        exit_status = v_exit_status,

Version-Release number of selected component (if applicable):
ovirt-engine-4.3.4.3-1.el7.noarch

How reproducible:
Always

Steps to Reproduce:
1. Have a Guest with agent running
2. Create 100 users in the VM, set password
$ for i in `seq 0 100` ; do useradd germano$i; done;
$ for i in `seq 0 100` ; do echo 'redhat' | passwd --stdin germano$i; done;
3. Login 100 users at the same time
$ for i in `seq 0 100` ; do screen -d -m sshpass -predhat ssh germano$i.150.159; done;

--- Additional comment from Germano Veit Michel on 2019-07-15 02:01:50 UTC ---

This is the one with the reproduction steps above:

2019-07-15 11:58:42,296+10 ERROR [org.ovirt.engine.core.dal.dbbroker.BatchProcedureExecutionConnectionCallback] (EE-ManagedThreadFactory-engineScheduled-Thread-74) [] Can't execute batch: Batch entry 0 select * from public.updatevmdynamic(CAST ('kernel-3.10.0-957.el7,ovirt-guest-agent-common-1.0.16-1.el7,qemu-guest-agent-2.12.0' AS text),CAST ('germano1, germano5, germano13, germano3, germano2, germano14, germano6, germano7, germano9, germano0, germano11, germano12, germano8, germano4, germano18, germano16, germano21, germano15, germano27, germano20, germano24, germano26, germano28, germano22, germano25, germano30, germano31, germano29, germano34, germano33, germano36, germano32, germano35, germano41, germano43, germano40, germano44, germano47, germano42, germano45, germano46, germano48, germano50, germano51, germano52, germano49, germano56, germano54, germano57, germano59, germano58, germano60, germano62, germano67, germano64, germano63, germano70, germano66, germano69, germano65, germano68, germano75, germano79, germano76, germano72, germano78, germano73, germano74, germano81, germano83, germano77, germano85, germano82, germano92, germano91, germano86, germano95, germano89, germano84, germano93, germano88, germano87, germano98, germano94, germano99, germano96, germano100' AS varchar),CAST (NULL AS varchar),CAST ('CentOS7' AS varchar),CAST (NULL AS uuid),CAST ('3.10.0-957.el7.x86_64' AS varchar),CAST (NULL AS uuid),CAST ('3034ef0c-9a41-44f9-8c1b-0520f83dd04d'::uuid AS uuid),CAST (1 AS int4),CAST ('372ec622-0878-429c-9eaf-bdb1b304b5e7'::uuid AS uuid),CAST ('localhost.localdomain' AS varchar),CAST ('192.168.150.159 fe80::23d6:15db:409c:2b58' AS varchar),CAST (NULL AS varchar),CAST ('2019-07-15 11:42:46.594+10' AS timestamptz),CAST ('2019-07-15 11:42:46.594+10' AS timestamptz),CAST (0 AS int8),CAST ('2019-07-15 11:26:35.776+10' AS timestamptz),CAST ('TRUE' AS bool),CAST (0 AS int4),CAST (0 AS int4),CAST (0 AS int4),CAST ('' AS varchar),CAST (NULL AS int4),CAST (0 AS int4),CAST (5 AS int4),CAST (NULL AS varchar),CAST (-2016404065 AS int4),CAST (NULL AS numeric),CAST (NULL AS varchar),CAST ('FALSE' AS bool),CAST ('FALSE' AS bool),CAST ('Skylake-Client,+spec-ctrl,+ssbd,+md-clear' AS varchar),CAST ('pc-i440fx-rhel7.6.0' AS varchar),CAST (NULL AS varchar),CAST (NULL AS varchar),CAST (-1 AS int4),CAST (1 AS int4),CAST (5901 AS int4),CAST (5902 AS int4),CAST ('192.168.150.2' AS varchar),CAST (5900 AS int4),CAST ('192.168.150.2' AS varchar),CAST (0 AS int4),CAST (0 AS int4),CAST (600 AS int4),CAST ('AEST' AS varchar),CAST (1 AS int4),CAST ('' AS varchar),CAST ('CentOS Linux' AS varchar),CAST ('3.10.0-957.el7.x86_64' AS varchar),CAST ('Linux' AS varchar),CAST ('7' AS varchar),CAST ('[]' AS text)) as result was aborted: ERROR: value too long for type character varying(255)
  Where: SQL statement "UPDATE vm_dynamic
    SET app_list = v_app_list,
        guest_cur_user_name = v_guest_cur_user_name,
        console_cur_user_name = v_console_cur_user_name,
        runtime_name = v_runtime_name,
        console_user_id = v_console_user_id,
        guest_os = v_guest_os,

--- Additional comment from Germano Veit Michel on 2019-07-15 03:51:23 UTC ---

Looks like the customer VMs are SSH proxies, waiting for confirmation of the use case.

--- Additional comment from Martin Perina on 2019-07-15 09:33:30 UTC ---

Ryan, could you please take a look?

--- Additional comment from Ryan Barry on 2019-07-15 11:17:32 UTC ---

This will require some careful testing, but it's worth checking whether we can change this to plain TEXT, or at least increase the size of the varchar field

--- Additional comment from Michal Skrivanek on 2019-07-16 04:20:10 UTC ---

Yeah.. did that for couple other fields already

--- Additional comment from Michal Skrivanek on 2019-07-16 06:45:30 UTC ---

zstream?

--- Additional comment from Ryan Barry on 2019-07-16 10:02:32 UTC ---

Clone once there's a patch