The Masking Logs will not show any error here. Blocks and Deadlocks when disabling/dropping Constraints (such as FKs).Blocks when creating MASKING_GENERATED_IDENTITY_TMP.However, there are also other locking scenarios: The lock above is the most common issue.A possible root cause here is FORWARDED RECORDS (which requires the SELECT to jump to another page in order to read the data).
#PAGE LOCK DEADLOCK SQL SERVER UPDATE#
#PAGE LOCK DEADLOCK SQL SERVER HOW TO#
What are SQL Server Deadlocks and how to monitor them.KBA: How to Troubleshoot Masking Jobs and Access Masking Logs (KBA7988).This includes Triggers (which should be disabled in this case). Ensure that there is no external transaction running which will change the data on the masked table.These will cause multiple scans / change the order.Depending on the Execution Plan, these might change the record order or cause multiple scans.Use a Clustered Index as the Unique Row Identifier (Key).The best option is when all rows are retrieved in a Logical Order (rows are fetched page by in consecutive order and each page only accessed once). A Clustered Index Scan will do this. The SELECT statement fetching the data will define the order in which data is read. These points will reduce the chance of encountering a hang (or deadlock). There are some best practices for an MS SQL In-Place masking job. KBA: Masking Method: On-The-Fly and In-Place (KBA1774).KBA: Masking Using READ_COMMITTED_SNAPSHOT (KBA6450)Īnother way to separate Read and Update on a table is to use On-The-Fly (OTF) masking:.If Clustered Index is not possible or if Complex Custom SQL is used - RCSI might be the way to go: If the block is on SELECT and UPDATE, then there are three tested solutions - these are:Ĭreating a Clustered Index is the sure way to resolve this issue. Go to Management > Extended Events > Sessions > system_health > package0.event_file.In the Object Explorer - open your database.
To view the Deadlock, open SQL Management Studio: SQL Server has a deadlock reporting tool. Use the following SQL commands (and look for blocked transactions): Use SQL Server to verify if and what Transaction is blocked. The logs are not showing any progress or useful info (since the engine is waiting for the database).The masking job is not starting (there might not be a row count).This is a special case and there can be blocks when the masking job is preparing for masking (like creating MASKING_GENERATED_IDENTITY_TMP). On the masking engine, the job never starts processing rows. ThroughputLogger:interval 0.000 MB (0 rows) counted in 30.000 sec throughput = 0.000 MB/sec The logs show no actions (there are multiple Throughput logger entries like this one):.The Masked Rows is stuck at a multiple of Commit Size -1 (for example 9,999).Masking performance drops without more records being masked.On the masking engine, there are some clear signs that the job has hung due to the Database blocks: Since masking uses multiple transactions, these locks can in rare cases cause the database operations to hang ( block). A special case of a block is when SQL Server detects the block and terminates a transaction - this terminates the execution with a Deadlock error.īelow is a high-level overview to Identify hung jobs and how to relate these to SQL Server: Usually, this happens (but not always) between SELECT and UPDATE. SQL Server uses locks on objects to prevent conflicts between concurrent transactions and ensure data consistency. This article details possible root causes and solutions to Blocks and Deadlocks on MS SQL Server.
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