Após a atualização do SQL Server 2014 para 2016, o servidor continua redefinindo planos de execução em cache e dm*
exibições (como dm_exec_query_stats
) etc. a cada duas horas
Como se alguém executasse DBCC FREEPROCCACHE
e DBCC DROPCLEANBUFFERS
manualmente (exceto por ninguém, isso acontece automaticamente).
O mesmo banco de dados funcionou bem no SQL Server 2014 e no Windows Server 2012; as coisas foram para o sul depois de mudar para o SQL Server 2016 (e Windows server 2016)
Coisas que verifiquei: o banco de dados não possui o sinalizador "fechar automaticamente". O servidor SQL está ad hoc optimized
definido como true
(eu pensei que ajudaria, não ajudou). O "repositório de consultas" está "desativado". O servidor possui 16 GB de memória.
Nada útil no "log do SQL Server" também. Apenas uma mensagem de backup semanal ...
Também verifiquei este artigo https://docs.microsoft.com/en-us/sql/t-sql/statements/alter-database-transact-sql-set-options (role para baixo até a seção "Exemplos" e logo acima ) existe uma lista de situações em que o plano é limpo automaticamente. Nenhuma delas se aplica.
ATUALIZAR:
Infelizmente, nenhuma das sugestões ajudou. Concedendo permissões LPIM, detectando e corrigindo consultas não parametrizadas que geraram vários planos para a mesma consulta, diminuindo a "memória máxima do servidor" ... Os planos continuam sendo redefinidos aleatoriamente, a cada duas horas a cada 5 a 10 minutos. Se o servidor estava "sob pressão de memória", como é que a versão de 2014 estava funcionando bem na mesma máquina.
Aqui está a saída sp_Blitz, conforme solicitado
**Priority 10: Performance**:
- Query Store Disabled - The new SQL Server 2016 Query Store feature has not been enabled on this database.
* xxx
**Priority 50: Server Info**:
- Instant File Initialization Not Enabled - Consider enabling IFI for faster restores and data file growths.
**Priority 100: Performance**:
- Resource Governor Enabled - Resource Governor is enabled. Queries may be throttled. Make sure you understand how the Classifier Function is configured.
**Priority 120: Query Plans**:
- Implicit Conversion Affecting Cardinality - One of the top resource-intensive queries has an implicit conversion that is affecting cardinality estimation.
*
- Missing Index - One of the top resource-intensive queries may be dramatically improved by adding an index.
*
- RID or Key Lookups - One of the top resource-intensive queries contains RID or Key Lookups. Try to avoid them by creating covering indexes.
*
**Priority 170: File Configuration**:
- System Database on C Drive
* master - The master database has a file on the C drive. Putting system databases on the C drive runs the risk of crashing the server when it runs out of space.
* model - The model database has a file on the C drive. Putting system databases on the C drive runs the risk of crashing the server when it runs out of space.
* msdb - The msdb database has a file on the C drive. Putting system databases on the C drive runs the risk of crashing the server when it runs out of space.
**Priority 200: Backup**:
- MSDB Backup History Not Purged msdb - Database backup history retained back to Jun 10 2017 9:47PM
**Priority 200: Informational**:
- Backup Compression Default Off - Uncompressed full backups have happened recently, and backup compression is not turned on at the server level. Backup compression is included with SQL Server 2008R2 & newer, even in Standard Edition. We recommend turning backup compression on by default so that ad-hoc backups will get compressed.
**Priority 200: Non-Default Server Config**:
- Agent XPs - This sp_configure option has been changed. Its default value is 0 and it has been set to 1.
- max server memory (MB) - This sp_configure option has been changed. Its default value is 2147483647 and it has been set to 15000.
- optimize for ad hoc workloads - This sp_configure option has been changed. Its default value is 0 and it has been set to 1.
- show advanced options - This sp_configure option has been changed. Its default value is 0 and it has been set to 1.
- xp_cmdshell - This sp_configure option has been changed. Its default value is 0 and it has been set to 1.
**Priority 200: Performance**:
- Buffer Pool Extensions Enabled - You have Buffer Pool Extensions enabled, and one lives here: Z:\sql_buffer_pool.BPE. It's currently 60.00000000000 GB. Did you know that BPEs only provide single threaded access 8KB (one page) at a time?
- cost threshold for parallelism - Set to 5, its default value. Changing this sp_configure setting may reduce CXPACKET waits.
**Priority 240: Wait Stats**:
- No Significant Waits Detected - This server might be just sitting around idle, or someone may have cleared wait stats recently.
**Priority 250: Informational**:
- SQL Server Agent is running under an NT Service account - I'm running as NT Service\SQLSERVERAGENT. I wish I had an Active Directory service account instead.
- SQL Server is running under an NT Service account - I'm running as NT Service\MSSQLSERVER. I wish I had an Active Directory service account instead.
**Priority 250: Server Info**:
- Default Trace Contents - The default trace holds 125 hours of data between Aug 19 2017 11:55AM and Aug 24 2017 4:59PM. The default trace files are located in: C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Log
- Hardware - Logical processors: 2. Physical memory: 15GB.
- Hardware - NUMA Config - Node: 0 State: ONLINE Online schedulers: 2 Offline schedulers: 0 Processor Group: 0 Memory node: 0 Memory VAS Reserved GB: 29
- Locked Pages In Memory Enabled - You currently have 12.02534484863 GB of pages locked in memory.
- Memory Model Unconventional - Memory Model: LOCK_PAGES
- Server Last Restart - Aug 20 2017 12:32PM
- Server Name - xx
- Services
- Service: SQL Full-text Filter Daemon Launcher (MSSQLSERVER) runs under service account NT Service\MSSQLFDLauncher. Last startup time: not shown.. Startup type: Manual, currently Running.
- Service: SQL Server (MSSQLSERVER) runs under service account NT Service\MSSQLSERVER. Last startup time: Aug 20 2017 12:32PM. Startup type: Automatic, currently Running.
- Service: SQL Server Agent (MSSQLSERVER) runs under service account NT Service\SQLSERVERAGENT. Last startup time: not shown.. Startup type: Automatic, currently Running.
- SQL Server Last Restart - Aug 20 2017 12:33PM
- SQL Server Service - Version: 13.0.4446.0. Patch Level: SP1. Edition: Enterprise Edition (64-bit). AlwaysOn Enabled: 0. AlwaysOn Mgr Status: 2
- Virtual Server - Type: (HYPERVISOR)
- Windows Version - You're running a pretty modern version of Windows: Server 2012R2 era, version 6.3
**Priority 254: Rundate**:
- Captain's log: stardate something and something...