整个过程中，升级tikv也没有问题，看起来是升级tidb-server之后开始有问题
怀疑是tidb server没有加载到统计信息
从升级过程中的日志来看 tidb server成功加载了 schema
但是stats 看着是加载失败了
还有一个这个错误
[handle_hist.go:125] [“SyncWaitStatsLoad meets error”] [errors="["sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load took too long to return","sync load stats channel is full and timeout sending task to channel","sync load stats channel is full and timeout sending task to channel","sync load stats channel is full and timeout sending task to channel","sync load took too long to return","sync load stats channel is full and timeout
实例的有几个表有分区，分区数如下：
相关stats参数如下
| information_schema_stats_expiry | 86400 |
| innodb_stats_auto_recalc | 1 |
| innodb_stats_method | nulls_equal |
| innodb_stats_on_metadata | 0 |
| innodb_stats_persistent | ON |
| innodb_stats_persistent_sample_pages | 20 |
| innodb_stats_sample_pages | 8 |
| innodb_stats_transient_sample_pages | 8 |
| myisam_stats_method | nulls_unequal |
| tidb_auto_build_stats_concurrency | 1 |
| tidb_build_sampling_stats_concurrency | 2 |
| tidb_build_stats_concurrency | 4 |
| tidb_enable_async_merge_global_stats | OFF |
| tidb_enable_extended_stats | OFF |
| tidb_enable_historical_stats | ON |
| tidb_enable_historical_stats_for_capture | OFF |
| tidb_enable_pseudo_for_outdated_stats | OFF |
| tidb_historical_stats_duration | 168h0m0s |
| tidb_merge_partition_stats_concurrency | 1 |
| tidb_plan_cache_invalidation_on_fresh_stats | OFF |
| tidb_skip_missing_partition_stats | ON |
| tidb_stats_cache_mem_quota | 0 |
| tidb_stats_load_pseudo_timeout | ON |
| tidb_stats_load_sync_wait | 100 |
